Voltage Controlled Oscillator on Quartz Substrate Spannungsgesteuerter Oszillator Auf Quarzsubstrat Oscillateur Contrôlé Par Tension Basé Sur Substrat De Quartz

(19) TZZ ¥ ZZ_T

(11) EP 2 320 560 B1

(12) EUROPEAN PATENT SPECIFICATION

(45) Date of publication and mention (51) Int Cl.: of the grant of the patent: H03B 5/12 (2006.01) H03B 5/18 (2006.01) 03.10.2012 Bulletin 2012/40

(21) Application number: 10186367.8

(22) Date of filing: 04.10.2010

(54) Voltage controlled oscillator on quartz substrate Spannungsgesteuerter Oszillator auf Quarzsubstrat Oscillateur contrôlé par tension basé sur substrat de quartz

(84) Designated Contracting States: • Fujiyama, Ryouichi AL AT BE BG CH CY CZ DE DK EE ES FI FR GB Sayama-shi Saitama 350-1321 (JP) GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR (74) Representative: TBK Bavariaring 4-6 (30) Priority: 05.10.2009 JP 2009231935 80336 München (DE)

(43) Date of publication of application: (56) References cited: 11.05.2011 Bulletin 2011/19 GB-A- 1 287 209 US-A- 5 532 651 US-A- 6 072 371 (73) Proprietor: Nihon Dempa Kogyo Co., Ltd. Shibuya-ku • PETER THOMA: "Absolute calorimetric Tokyo 151-8569 (JP) determination of dielectric loss factors at w = 10 4 s -1 and 4.2 k and application to the (72) Inventors: measurement of loss factors of standard • Tsuda, Toshimasa capacitors at room temperature", IEEE Sayama-shi Saitama 350-1321 (JP) TRANSACTIONS ON INSTRUMENTATION AND • Onzuka, Tatsunori MEASUREMENT, IEEE SERVICE CENTER, Sayama-shi Saitama 350-1321 (JP) PISCATAWAY, NJ, US, vol. 15, no. 4, 1 December • Kawahata, Kenji 1980 (1980-12-01), pages 328-330, XP011246154, Sayama-shi Saitama 350-1321 (JP) ISSN: 0018-9456 • Hoshigami, Hiroshi Sayama-shi Saitama 350-1321 (JP)

Note: Within nine months of the publication of the mention of the grant of the European patent in the European Patent Bulletin, any person may give notice to the European Patent Office of opposition to that patent, in accordance with the Implementing Regulations. Notice of opposition shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). EP 2 320 560 B1

Printed by Jouve, 75001 PARIS (FR) 1 EP 2 320 560 B1 2

Description However, in the case of a), a phase noise becomes large since a multiplication circuit is used. Further, in the case [0001] The present invention relates to a technique for of b), the cost is increased, and in the case of c), the size forming a resonance part using an inductance element is large so that it becomes difficult to realize the down- and a variable capacitance element, and a voltage con- 5 sizing. trolled oscillator (VCO) using the resonance part. [0006] Although Patent Document 1 describes a de- [0002] As shown in Fig. 13, for instance, a voltage con- vice such as the above-described VCO, no study has trolled oscillator (VCO) includes a resonance part having been made regarding the aforementioned problems. Fur- a varicap diode VD whose electrostatic capacitance var- ther, according to Patent Document 2, there is known a ies in accordance with a control voltage and an induct- 10 technique for making a quartz crystal being a piezoelec- ance element 11, and a feedback part 2 formed of a tran- tric substrate generate an elastic wave to use the quartz sistor 21 being an amplifying part and two capacitors C1, crystal as a resonator whose oscillation frequency is in C2. In this example, a frequency signal resonated in the about several MHz band, for instance, but, it is not pos- resonance part is amplified by the transistor 21, and is sible to solve the above-described problems. fed back to a series resonant circuit via the feedback part 15 [0007] [Patent Document 1] Japanese Patent Applica- 2, thereby forming an oscillation loop. Note that 31 in Fig. tion Laid-open No. Hei 10-209714 [Patent Document 2] 13 denotes a buffer amplifier that amplifies the frequency Japanese Patent Application open Laid- No. signal and outputs it to the outside. Further, 16, T3 and 2007-201772 L denote an input terminal, an output terminal part and [0008] Further prior art, which refers to this technical an inductance element, respectively. Although the illus- 20 field can be found in document US 5,532,651, disclosing tration is omitted, the VCO is disposed on a base sub- a "tunable voltage controlled oscillator having microstip strate made of ceramics such as LTCC (Low Tempera- resonator with cuts for better tuning". ture Co-fired Ceramics) using alumina (Al 2O3) as a main [0009] Further prior art, which refers to this technical component, for instance. field can be found in document US 6,072,371, disclosing [0003] Here, if the VCO is used in a high frequency 25 a "quenchable VCO for switched band synthesizer ap- band of, for example, several GHz or several tens of GHz plications". by increasing an oscillation frequency thereof, problems [0010] The present invention has been made based as follows occur. Specifically, in a high frequency band, on such circumstances, and an object thereof is to pro- the VCO may become a distributed constant circuit in vide a voltage controlled oscillator capable of being treat- whicha size of the substrate becomeslarger than a wave- 30 ed as a lumped constant circuit, having small size and length of electrical signal processed (output) by the capable of obtaining an oscillation frequency in a high above-described VCO, and in such a case, there is a frequency band. possibility such that signals whose amplitudes are re- [0011] The object is solved by what is defined in claim versed flow on the substrate, and these signals interfere 1. with each other, which results in outputting no electrical 35 [0012] A further advantageous modification is set forth signal, or the size of the substrate including the VCO has in claim 2. to be reduced to a size with which a practical manufac- [0013] According to the present invention, a voltage turing becomes difficult. controlled oscillator is formed by providing a resonance [0004] For instance, the VCO is disposed on a not- part and a feedback part on a quartz-crystal substrate shown base substrate made of ceramics such as LTCC 40 whose relative dielectric constant ε is small to be about using alumina (Al2O3) as a main component. The LTCC 4.0, so that even when the voltage controlled oscillator has a relative dielectric constant ε of about 9 to 10, for is formed on a substrate which is larger than a substrate example, so that an apparent wavelength of electrical madeof ceramics, for instance, theoscillator can be treat- signal propagating on the substrate becomes shorter ed as a lumped constant circuit, which enables a frequen- than an actual wavelength. Accordingly, in order to sup- 45 cysignal ina high frequency band of, forexample, several press the interference of electrical signals, it is preferable GHz or several tens of GHz to be stably oscillated. to reduce a size of the substrate to, for example, about 1/10 of the wavelength of the electrical signal, but, in Fig. 1 is a circuit diagram showing a VCO as an ex- reality, it is difficult to form electric circuits or mount elec- ample of an embodiment of an electric circuit of the tronic components on a substrate with such a size. 50 present invention; [0005] Furthermore, in a VCO mounted in a radio com- Fig. 2 is a perspective view showing an external ap- munication device that outputs an electrical signal with pearance of the above-described VCO; a quite high frequency, which is, for example, an electrical Fig. 3 is a plan view showing the above-described signal in a GHz band (microwave), it is conceivable that VCO; a) an output signal of the VCO outputting a signal having 55 Fig. 4 is a side view showing the above-described a frequency lower than the frequency band is multiplied, VCO; b) GaAs (gallium arsenide compound) or the like is used Fig. 5 is an enlarged plan view showing the above- as a base substrate, and c) a cavity resonator is used. described VCO;

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Fig. 6 is a plan view showing a circuit part on sub- itor 12, and a series circuit of capacitors 22, 23 serving strate of the above-described VCO; as feedback capacitance elements and connected be- Fig. 7 is a side view showing the above-described tween a connection point between the capacitor 12 and circuit part on substrate; the base of the transistor 21 and a ground. An emitter of Fig. 8 is an enlarged plan view showing the above- 5 the transistor 21 is connected to a connection point be- described circuit part on substrate; tween the capacitors 22 and 23, and grounded via an Fig. 9 is a characteristic diagram showing an output inductance 24 and a resistance 25. The transistor 21 is frequency characteristic obtained by the above-de- provided in a chip of an IC circuit part (LSI) 3 indicated scribed VCO; by a dotted line, and the base and the emitter of the tran- Fig. 10 is a characteristic diagram showing a phase 10 sistor 21 are respectively connected to both ends of the noise characteristic obtained by the above-de- capacitor 22 via terminal parts (electrodes) T1, T2 of the scribed VCO; chip. Fig. 11 is a plan view showing an another configu- [0017] In the circuit according to the present example, ration example of the above-described circuit part when the control voltage is input into the input terminal on substrate; 15 16 from the outside, oscillation is made at a frequency Fig. 12 is a flow diagram showing an example of a of the resonance point, which is, for example, 10 GHz, forming method of the above-described VCO; and by an oscillation loop formed of the resonance part 1 and Fig. 13 is an electrical diagram showing a configu- the feedback part 2. ration of a conventional VCO. In the IC circuit part 3, there are provided two buffer am- 20 plifiers 31, 32 connected in parallel with each other to a [0014] Before describing a structure of an embodiment collector of the transistor 21, for example, in which it is of a voltage controlled oscillator (VCO) of the present structured such that an oscillation output (signal of oscil- invention, a circuitry of the embodiment will be described lation frequency) is taken out from one buffer amplifier with reference to Fig. 1. In Fig. 1, 1 denotes a resonance 31 via a terminal part T3, and an oscillation output is part, and the resonance part 1 is provided with a series 25 taken out from the other buffer amplifier 32 via a frequen- circuit for series resonance including an inductance ele- cy dividing circuit 33 and a terminal part T4. ment 11 formed of a conductive line 48 as will be de- [0018] Note that the resonance part 1 may also have scribed later and a capacitor 12 being a capacitance el- a circuitry in which the varicap diode and the inductance ement. A series circuit formed of a first varicap diode 13, element 11 are serially connected and an oscillation fre- a second varicap diode 14 and a capacitor 15 being a 30 quency is determined by a series resonance frequency capacitance element is connected in parallel with the in- of the series circuit, and in this case, the varicap diode ductance element 11, which forms a parallel circuit for also serves as the capacitance element in the resonance parallelresonance. Specifically, the resonance part 1 has part 1 in "WHAT IS CLAIMED IS" in the present invention. a series resonance frequency (resonance point) of the [0019] Next, a concrete overview of the VCO and a seriescircuit and a parallel resonance frequency (antires- 35 layout of the above-described resonance part 1 and the onance point) of the parallel circuit, and an oscillation feedback part 2 as well as the circuit part 3 will be de- frequency is determined by a frequency of the resonance scribed with reference to Fig. 2 to Fig. 5. The VCO is point. In this example, a constant of each circuit element formed on, for instance, an AT-cut quartz-crystal sub- is set so that the resonance point becomes greater than strate 5, and on the quartz- crystal substrate 5, there are the antiresonance point, and by providing the antireso- 40 disposed electronic components formed of a later-de- nance point as above, a frequency characteristic in the scribed circuit part on substrate 10 including the reso- vicinity of the resonance point becomes steep. nance part 1 and the capacitors 22, 23 in the feedback [0015] Further, in Fig. 1, 16 denotes an input terminal part 2 and the IC circuit part 3 as well as a peripheral for control voltage, and by a control voltage supplied to component and the like. the input terminal 16, capacitance values of the first var- 45 [0020] On the quartz-crystal substrate 5, there is icap diode 13 and the second varicap diode 14 are ad- formed a coplanar line having a ground electrode 51 and justed. Accordingly, the antiresonance point of the par- conductive lines 6 for electrically connecting the above- allel circuit is shifted, and as a result of this, the resonance described respective electronic components on the point is also shifted, which results in adjusting the oscil- quartz-crystal substrate 5 and formed of a metal film in lation frequency. The reason why the second varicap di- 50 which, for example, Cr (chromium) and Cu (copper) are ode 14 is used in addition to the first varicap diode 13 is laminated in this order from the bottom, in which these to secure a large span of adjustable range of frequency. ground electrode 51 and conductive lines 6 are disposed 17 denotes a capacitor for voltage stabilization, and 18, to be separated from each other, as shown in Fig. 5. Note 19 are bias inductors. that a part of an area on the quartz- crystal substrate 5 is [0016] Further, a feedback part 2 is provided on a rear 55 cut out and enlarged to be illustrated in Fig. 5, in which stage side of the resonance part 1, and the feedback part hatching is provided in an area corresponding to the 2 includes an NPN-type transistor 21 serving as an am- ground electrode 51 and the later-described circuit part plifying part and having its base connected to the capac- on substrate 10. Further, in Fig. 5, the conductive lines

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6 respectively connected to connecting terminals 8 for 10 together with the above-described capacitors 12, 15, the aforementioned base, emitter and collector of the 22, 23 is formed as a strip line being a conductive line, transistor 21, among a plurality of connecting terminals as shown in Fig. 6, for instance. Further, as shown in Fig. 8 of the circuit part 3, are denoted by symbols of B, E 6, if an area, in the inductance element 11, sandwiched and C, respectively. 5 by the two capacitors 12 and 15 is set as one end side [0021] Among the above- described electronic compo- of the inductance element 11, the other end side of the nents, the respective electronic components except the inductance element 11 and the common electrode part circuit part on substrate 10 are respectively fixed on the 60, of the capacitor 23, on the opposite side of the com- quartz-crystal substrate 5 by connecting parts 7 such as, mon electrode part 60 connected to the emitter are con- for example, solder balls, and the respective connecting 10 nected to the ground electrode 51 formed on a surface terminals 8 and the conductive lines 6 are electrically of the quartz-crystal substrate 5. connected, as shown in Fig. 4. Further, although the il- Here, Fig. 7 shows a vertical sectional side view in which lustration is omitted in Fig. 2 and the like, these electronic the quartz- crystal substrate 5 is cut along A- A’ line shown components are connected by the above-described con- in Fig. 6, and Fig. 8 is a view showing a part of the circuit ductive lines 6 routed around on the quartz- crystal sub- 15 part on substrate 10 shown in Fig. 6 in an enlarged man- strate 5, thereby configuring an electric circuit that forms ner. the VCO as shown in the aforementioned Fig. 1. In Fig. [0026] In the VCO, when a voltage for control (control 3, 20 denotes a bias circuit for supplying a bias voltage voltage) is applied to the input terminal 16, oscillation is to the transistor 21, and the bias circuit 20 is grounded. made at a frequency of the resonance point, which is, for Note that the illustration of conductive lines 6 is omitted 20 example, 10 GHz, by the oscillation loop formed of the in Fig. 2, and further, Fig. 3 to Fig. 5 illustrate only a part resonance part 1 and the feedback part 2 as described of the conductive lines 6. above, and a frequency signal corresponding to the os- [0022] As shown in Fig. 2 and Fig. 3 as well as Fig. 6 cillation frequency and a divided output of the frequency and Fig. 7, the inductance element 11, the capacitors 12, signal are taken out from the terminal part T3 and the 15 in the above- described resonance part 1, and the ca- 25 terminal part T4, respectively. Here, at the time of the pacitors 22, 23 in the feedback part 2 are directly formed, oscillation, the resonance part 1 has an inductivity. At by photolithography or the like, within a predetermined this time, since the dielectric loss tangent of the quartz- area on an upper surface side, for example, of the quartz- crystal substrate 5 is quite small as described above and crystal substrate 5 on which the electronic components thus a high Q value is provided, when compared to a such as the circuit part 3 and the varicap diode 14 are 30 conventional substrate made of, for instance, fluorocar- disposed. Hereinafter, if a circuit part including the in- bon resin (Q value = 1000), the quartz- crystal substrate ductance element 11, the capacitors 12, 15 in the reso- 5 can reduce the phase noise to quite a low level over a nance part 1 and the capacitors 22, 23 in the feedback wide frequency adjustment band. Specifically, a variable part 2 and formed within the area is referred to as a circuit range of frequency in which a low phase noise charac- part on substrate 10, the circuit part on substrate 10 is 35 teristic can be obtained is wide. Results of simulations also connected to the circuit part 3 or the like by the con- performed with respect to the VCO are shown in Fig. 9 ductive lines 6 formed on the quartz-crystal substrate 5 and Fig. 10, in which it can be confirmed that it is possible as shown in Fig. 4, Fig. 5, for example, to thereby form to adjust an output frequency in a frequency band of GHz the VCO. band in accordance with a control voltage, and further, [0023] For example, the quartz- crystal substrate 5 has 40 it is possible to obtain a phase noise characteristic, which a relative dielectric constant ε within a range of about 3 is better than a conventional characteristic, over a wide to 5, which is, for example, 4.0, and a loss of electric bandwidth. Note that Fig. 10 shows a phase noise at a energy (dielectric loss tangent : tanδ ) which is about position displaced by 10 kHz from the oscillation frequen- 0.00008. Therefore, a Q value of the quartz- crystal sub- cy. For reference, Fig. 10 additionally shows a charac- 45 strate 5 becomes about 12500 (= 1/0.00008). teristic of Al 2O3 (HTCC : High Temperature Co- fired Ce- [0024] Although the illustration is simplified in Fig. 6, ramic, tan δ = 0.001, Q value = 10000), for example. each of the capacitors 12, 15, 22, 23 forming the circuit Further, Fig. 10 shows a result obtained by calculating a part on substrate 10 is actually formed of a comb elec- characteristic at the time of unloaded state (state where trode including a pair of common electrode parts 60 the inductance element 11 and the capacitors 12, 15, 22, formed to be parallel to each other, for example, and a 50 23 are not mounted on the quartz-crystal substrate 5). group of electrode fingers (conductive paths) 61 extend- [0027] Further, since the inductance element 11, the ing in a comb-teeth shape from the respective common capacitors 12, 15 in the resonance part 1 and the capac- electrode parts 60 and intersecting with one another, and itors 22, 23 in the feedback part 2 are formed on the the respective common electrode parts 60 are connected quartz-crystal substrate 5 with a small relative dielectric to the connecting terminal 8 and the inductance element 55 constant as the circuit part on substrate 10, when com- 11. pared to a case where the circuit part on substrate 10 is [0025] Meanwhile, the inductance element 11 in the formed on the conventional LTCC, for instance, it is pos- resonance part 1 included in the circuit part on substrate sible to increase an apparent wavelength of frequency

4 7 EP 2 320 560 B1 8 signal oscillated by the circuit part on substrate 10. loss of electrical signal. [0028] For instance, a wavelength of a frequency sig- When an electric power value required for an actual op- nal of 10 GHz in a vacuum is about 3 cm, and meanwhile, eration, including that of a frequency divider, is checked a wavelength of the frequency signal in a dielectric has in the VCO of the present invention, a voltage and a cur- a value equal to a value obtained by dividing the wave- 5 rent are about 3.5 V and 75 mA, respectively. On the length in the vacuum by a value being one- half power of other hand, when a characteristic of VCO which uses a relative dielectric constant of the dielectric, so that when conventional GaAs as a base substrate 5 is checked in a relative dielectric constant s of the quartz- crystal sub- the same manner, a voltage and a current are about 5 V strate 5 is 4.0, an apparent wavelength of the frequency and 300 mA, respectively. Therefore, it is confirmed that signal becomes about 1.5 cm. Accordingly, as described 10 the VCO of the present invention can reduce power con- in "DESCRIPTION OF THE RELATED ART", by forming sumption more than the conventional VCO. the circuit part on substrate 10 within an area of about [0031] Here, a quartz crystal has been used as a pie- 1/10 of the apparent wavelength of the frequency signal, zoelectric element in a device utilizing an elastic wave, namely, an area of about 1.5 mm to 2.0 mm, it becomes and the present invention focuses attention on excellent possible to treat the circuit part on substrate 10 as a15 physical properties (tan δ and relative dielectric constant lumped constant circuit. If an area of about 1.5 mm to ε) of the quartz crystal and a point such that a fine pattern 2.0 mm is provided, it is feasible to form the aforemen- of metal film can be formed on a surface of the quartz tioned comb-like electrodes and strip line formed of the crystal with the use of the photolithography method, and conductive line by using photolithography, which enables forms the inductance element 11, the capacitors 12, 15 to mass-produce the VCOs each having the quartz- crys- 20 forming the resonance part 1 and the capacitors 22, 23 tal substrate 5 on which the circuit part on substrate 10 in the feedback part 2 on the quartz-crystal substrate 5. is formed, while suppressing the reduction of the yield Further, the present example describes a configuration and the like. example in which on the quartz-crystal substrate 5 on [0029] According to the above- described embodiment, which the circuit part on substrate 10 is formed, the other since there is used the quartz- crystal substrate 5 having 25 circuit part 3, varicap diode 14 and the like are disposed, characteristics (relative dielectric constant ε, tan δ) better but, these other circuits 3, 14 are not necessarily dis- than those of fluorocarbon resin, LTCC or the like con- posed on the quartz-crystal substrate 5. For instance, a ventionally used as a substrate of the inductance element case in which the respective elements (the inductance 11 and the capacitor 12, and on which a fine pattern of element 11, the capacitors 12, 15 in the resonance part metal film can be formed through a photolithography30 1, and the capacitors 22, 23 in the feedback part 2) in- method, it is possible to obtain a low phase noise char- cluded in the circuit part on substrate 10 shown in Fig. 6 acteristic over a wide adjustment band. Further, by form- to Fig. 8 are formed on a common quartz-crystal sub- ing the inductance element 11, the capacitors 12, 15 in strate to separately manufacture a quartz- crystal chip ca- the resonance part 1 and the capacitors 22, 23 in the pable of being treated as a lumped constant circuit, and feedback part 2 (circuit part on substrate 10) on the35 the quartz-crystal chip is disposed on a substrate made quartz-crystal substrate, it becomes possible to treat the of, for example, fluorocarbon resin or LTCC on which the circuit part on substrate 10 as a lumped constant circuit other circuit part 3, varicap diode 14 and the like are dis- and to make a frequency signal in a high frequency band posed, to thereby form the VCO, is also included. of, for example, several GHz or several tens of GHz to [0032] Further, each of the above-described capaci- be stably oscillated. 40 tors 12, 15, 22, 23 may also be configured such that two [0030] Further, since the inductance element 11, and electrode lines, for instance, instead of the comb elec- the capacitors 12, 15, 22, 23 can be formed in one chip trode, are provided so as to face each other and an elec- with the use of the photolithography method, it is possible tric charge is accumulated between the lines, or a multi- to obtain the resonance part 1 and the VCO which are layer ceramic capacitor may also be used as the above- small size and durable to physical shock in an inexpen- 45 described capacitor. sive manner. Further, by configuring the capacitors 12, Further, as a layout of the conductive line 48 on the 15, 22, 23 by the comb electrodes using the photolithog- quartz-crystal substrate 5, it is also possible that the in- raphy method as described above, large opposing areas ductance element 11 is routed around on the quartz- crys- (charge storage areas) of each of the electrode fingers tal substrate 5, as shown in Fig. 11, for example. 61, 61 can be provided, so that capacitors having small 50 [0033] Further, as a material forming the conductive size and low loss can be easily obtained. Further, since lines 6, the capacitors 12, 15, 22, 23, and the inductance the inductance element 11 and the capacitors 12, 15, 22, element 11 on the quartz-crystal substrate 5, it is also 23 can be directly formed on the quartz- crystal substrate possible to use at least one kind of Cu (copper), Au (gold), 5, it is possible to shorten the routing of the electrode Cr (chromium), Ni (nickel), Ti (titanium), W (tungsten), V (conductive path), compared to a case where electronic 55 (vanadium), Ta (tantalum), Mo (molybdenum), Ag (sil- components corresponding to these inductance element ver), Pd (palladium), In (indium) and Sn (tin), for example, 11 and capacitors 12, 15, 22, 23 are mounted, for in- other than aluminum. stance, and accordingly, it is possible to suppress the Further, in the above- described example, the two varicap

5 9 EP 2 320 560 B1 10 diodes 13, 14 are disposed, but, it is also possible to which intersect with a space therebetween, and dispose one of them, and further, it is also possible to an inductance element (11) being a conductive make one of these varicap diodes 13, 14 function as the path formed directly on the quartz-crystal sub- capacitor 12, as shown in the aforementioned Fig. 13. strate (5), the series resonance frequency of [0034] Subsequently, an example of a method of man- 5 said resonance part being adjusted in accord- ufacturing the above-described VCO will be described. ance with the electrostatic capacitance; First, a general outline of the manufacturing method will a feedback part (2) including an amplifying part be described. As shown in Fig. 12, a large number of (21) amplifying a frequency signal from said res- comb electrodes described above are formed, on a onance part (1), the amplifying part being pro- quartz-crystal wafer 40 having a diameter of 10 cm, for 10 vided in a chip of an IC circuit part (3), wherein example, in a layout shown in the aforementioned Fig. 6 the feedback part (2) has a feedback capaci- as the capacitors 12, 15, 22, 23 (step S11), and subse- tance element (22, 23) formed of a pair of comb- quently, the conductive line 48 is disposed on the quartz- like conductive paths, which are formed directly crystal wafer 40 to form a pattern of the inductance ele- on a quartz-crystal substrate (5) and which in- ment 11, thereby forming the circuit part on substrate 10 15 tersect with a space therebetween, and forms as well as forming the ground electrode 51 (step S12). an oscillation loop together with said amplifying Next, the quartz-crystal wafer 40 is cut by dicing or the part (21) and said resonance part (1) by making like, for instance, so that the aforementioned quartz- crys- the frequency signal amplified in said amplifying tal substrate 5 is divided into pieces (divided into chips) part (21) to be fed back to said resonance part (step S13), and the components such as the IC circuit 20 (1), characterized in that part 3 and the varicap diode 14 are mounted on the the variable capacitance element (13, 14) and quartz-crystal substrate 5 via the solders (connecting the IC circuit part (3) are mounted on the sub- parts 7) printed on the quartz-crystal substrate 5 having strate via connecting parts (7). a wafer shape, for instance (step S 14). Thereafter, a not-shown cap is mounted to cover the respective com- 25 2. The voltage controlled oscillator according to claim ponents on the quartz-crystal substrate 5 (step S15), 1, wherein the series resonance frequency is 5 GHz thereby manufacturing the VCO. or more. Toprovide a voltage controlledoscillator capableof being treated as a lumped constant circuit, having small size and capable of obtaining an oscillation frequency in a 30 Patentansprüche high frequency band. A resonance part 1 in a voltage controlled oscillator has variable capacitance elements 1. Spannungsgesteuerter Oszillator (VCO) mit: 13, 14 whose electrostatic capacitance varies in accordance with a control voltage for frequency control input einem Resonanzteil (1) mit einem variablen ka- from the outside and an inductance element 11, an am- 35 pazitiven Element (13, 14), das eine Varicap- plifying part 21 amplifies a frequency signal from the res- Diode ist, deren elektrostatische Kapazität ge- onance part 1, and a feedback part 2, having feedback mäß einer Steuerspannung für eine Frequenz- capacitance elements 22, 23, forms an oscillation loop steuerungseingabe von außerhalb variiert, ei- together with the amplifying part 21 and the resonance nem kapazitiven Element (12, 15), dessen Ka- part 1 by making the frequency signal amplified in the 40 pazität nicht durch die Spannung variiert wird amplifying part 21 to be fed back to the resonance part und das aus einem Paar von kammähnlichen 1. Further, the resonance part 1 and the feedback part 2 leitfähigen Pfaden gebildet ist, die direkt auf ei- are provided on a quartz-crystal substrate 5. nem Quartzkristallsubstrat (5) gebildet sind und die sich mit einem Raum zwischen ihnen kreu- 45 zen, und einem induktiven Element (11), das ein Claims leitfähiger Pfad ist, der direkt auf dem Quartz- kristallsubstrat (5) gebildet ist, wobei die Seri- 1. A voltage controlled oscillator (VCO), comprising: enresonanzfrequenz des Resonanzteils gemäß der elektrostatischen Kapazität eingestellt ist; a resonance part (1) having a variable capaci- 50 einem Rückkopplungsteil (2) einschließlich ei- tance element (13, 14) being a varicap diode, nem Verstärkungsteil (21), das ein Frequenzsi- whose electrostatic capacitance varies in ac- gnal von dem Resonanzteil (1) verstärkt, wobei cordance with a control voltage for frequency der Verstärkungsteil auf einem Chip auf einem control input from the outside, a capacitance el- IC-Schaltteil (3) bereitgestellt ist, wobei der ement (12, 15) whose capacitance is not varied 55 Rückkopplungsteil (2) ein kapazitives Rück- by the voltage and which is formed of a pair of kopplungselement (22, 23) aufweist, das aus ei- comb-like conductive paths, which are formed nem Paar von kammähnlichen leitfähigen Pfa- directly on a quartz-crystal substrate (5) and den gebildet ist, die direkt auf einem Quartzkri-

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stallsubstrat (5) gebildet sind und die sich mit nexion (7). einem Raum zwischen ihnen kreuzen, und zu- sammen mit dem Verstärkungsteil (21) und dem 2. Oscillateur commandé en tension selon la revendi- Resonanzteil (1) dadurch eine Oszillations- cation 1, dans lequel la fréquence de résonance en schleife bildet, dass es das in dem Verstär-5 série est supérieure ou égale à 5 GHz. kungsteil (21) verstärkte Frequenzsignal in den Resonanzteil (1) rückkoppelt,dadurch ge- kennzeichnet, dass dasvariable kapazitive Element(13, 14) und das IC-Schaltteil (3) auf dem Substrat über verbin- 10 dende Teile (7) montiert sind.

2. Spannungsgesteuerter Oszillator nach Anspruch 1, wobeidie Serienresonanzfrequenz5 GHz odermehr ist. 15

Revendications

1. Oscillateur commandé en tension (VCO), 20 qui comprend :

une partie de résonance (1) comportant un élé- ment à capacitance variable (13, 14) qui est une diode varicap, dont la capacitance électrostati- 25 que varie conformément à une tension de commande pour une commande de fréquence intro- duite de l’extérieur, un élément capacitif (12, 15) dont la capacitance n’est pas modifiée par la tension, et qui est formé d’une paire de chemins 30 conducteurs en forme de peigne, qui sont for- més directement sur un substrat en quartz (5) et qui se croisent avec un espace entre eux, et un élément d’inductance (11) qui est un chemin conducteur formé directement sur le substrat en 35 quartz (5), la fréquence de résonance en série de ladite partie de résonance étant réglée con- formément à la capacitance électrostatique ; une partiede rétroaction (2) comportantune partie d’amplification (21) amplifiant un signal de 40 fréquence provenant de ladite partie de réso- nance (1), la partie d’amplification étant prévue dans une puce d’une partie de circuit intégré (3), où la partie de rétroaction (2) possède un élé- ment capacitif de rétroaction (22, 23) formé45 d’une paire de chemins conducteurs en forme de peigne qui sont formés directement sur un substrat en quartz (5) et qui se croisent avec un espace entre eux, et forme une boucle d’oscillation conjointement avec ladite partie d’amplifi- 50 cation (21) et ladite partie de résonance (1) en permettant au signal de fréquence amplifié dans ladite partie d’amplification (21) d’être renvoyé à ladite partie de résonance (1), caractérisé en ce que 55 l’élément à capacitance variable (13, 14) et la partie de circuit intégré (3) sont montés sur le substrat par l’intermédiaire de parties de con-

7 EP 2 320 560 B1

8 EP 2 320 560 B1

9 EP 2 320 560 B1

10 EP 2 320 560 B1

11 EP 2 320 560 B1

12 EP 2 320 560 B1

13 EP 2 320 560 B1

14 EP 2 320 560 B1

15 EP 2 320 560 B1

16 EP 2 320 560 B1

17 EP 2 320 560 B1

18 EP 2 320 560 B1

REFERENCES CITED IN THE DESCRIPTION

This list of references cited by the applicant is for the reader’s convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

Patent documents cited in the description

• JP HEI10209714 B [0007] • US 5532651 A [0008] • JP 2007201772 A [0007] • US 6072371 A [0009]