JPH10270938A - Oscillation circuit device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the wide variable range of an oscillated frequency over a higher frequency range by forming an inductive element that is a component of an LC resonance circuit forming part together with a capacitive element by means of not an air-core coil but a pattern conductor provided to a printed circuit board. SOLUTION: This device is provided with an oscillation circuit forming part 12 and an LC resonance circuit forming part 24 connecting thereto, and the LC resonance circuit forming part 24 includes varactor diodes 15, 16 placed on a printed circuit board 11 and an inductive element made of a pattern conductor 17 provided to a front side of the printed circuit board 11. Then throughholes 25, 26 are made in the vicinity of the pattern conductor 17 of the printed circuit board 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frequency converter for performing frequency conversion on a received radio transmission signal having a relatively high carrier frequency to obtain an intermediate frequency signal of a predetermined frequency. The present invention relates to a suitable oscillation circuit device.

[0002]

2. Description of the Related Art In a tuner apparatus of a superheterodyne receiving system which is generally used for selectively receiving a plurality of radio transmission signals, a selection device for converting a carrier frequency of a selectively received radio transmission signal into an intermediate frequency is used. A mixer unit to which the received wireless transmission signal is supplied and a local oscillation unit to supply an oscillation output signal for frequency conversion to the mixer unit are provided. The local oscillator is configured to output an oscillation output signal to be supplied to the mixer unit so that an intermediate frequency signal having a predetermined constant intermediate frequency is obtained from the mixer unit based on the selectively received radio transmission signal. The variable frequency oscillating unit changes the frequency according to the carrier frequency of the radio transmission signal selectively received.

An LC resonance circuit forming section provided in such a local oscillation section as a variable frequency oscillating section generally comprises a variable capacitance element and an inductive element to form a resonance circuit, and changes the capacitance of the variable capacitance element. Thereby changing the resonance frequency that determines the oscillation frequency in the local oscillator. As the variable capacitance element, a variable capacitance diode that changes a capacitance value according to a change in a voltage value applied between both ends is used, and as an inductive element, an air-core coil is often used.

However, for example, there is a tuner device that selectively receives a radio transmission signal having a relatively high carrier frequency, such as a satellite tuner device that selectively receives a satellite broadcast signal transmitted under a satellite broadcast system. In addition, since the inductive element constituting the LC resonance circuit forming section provided in the local oscillation section can reduce the cost under the demand for miniaturization, the local oscillation section having the LC resonance circuit forming section is constituted. Various elements are arranged on a printed wiring board, and are formed by pattern conductors provided on the surface of the wiring board. The pattern conductor provided on the surface of the wiring board that forms such an inductive element is, for example, linearly extended in a thin band shape.

[0005]

As described above, for example, an inductive element constituting an LC resonance circuit forming section provided in a local oscillation section in a satellite tuner device is formed by a pattern conductor provided on a surface of a wiring board. In this case, the wiring board provided with the pattern conductor forming the inductive element on the surface acts as a dielectric, and an unnecessary capacitance is formed between the pattern conductor forming the inductive element and the ground potential point. become. Unnecessary capacitance formed between the pattern conductor forming the inductive element and the ground potential point is caused by the inductive element formed by the pattern conductor and the variable capacitance element, for example, a variable capacitance diode. The formed LC resonance circuit forming section has an effect of restricting a variable range of the resonance frequency of the resonance circuit formed by the LC resonance circuit forming section.

The fact that the variable range of the resonance frequency of the resonance circuit formed by the LC resonance circuit forming section provided in the local oscillation section is restricted is limited by the local oscillation determined by the resonance frequency of the resonance circuit formed by the LC resonance circuit forming section. The variable range of the oscillation frequency of the part will be restricted,
Therefore, for example, the reception frequency range of the satellite tuner device provided with the local oscillation unit is limited. Therefore, for example, among the satellite tuner devices, in particular, in a digital satellite tuner device which is required to have a wide frequency range on the high frequency side as a reception frequency range, an LC resonance provided in a local oscillation unit provided in the tuner device is provided. An inductive element having a circuit forming portion formed of a variable capacitance element such as a variable capacitance diode can provide an extremely wide variable range of a resonance frequency required for a resonance circuit formed by the LC resonance circuit forming portion. Therefore, instead of being formed by the pattern conductor provided on the surface of the wiring board, for example, an air-core coil is formed. As a result, costs associated with the use of the air-core coil, such as the work of attaching the air-core coil to the printed wiring board and the adjustment work after mounting the air-core coil on the printed wiring board, are reduced. Soaring.

In view of the above, the present invention includes an LC resonance circuit forming portion, and an inductive element that forms the LC resonance circuit forming portion together with a capacitive element is provided not on an air-core coil but on the surface of a wiring board. Under the formation by the pattern conductors, a relatively wide variable range in the relatively high frequency range of the oscillation frequency can be obtained, and therefore without any disadvantages due to the use of air-core coils, Provided is an oscillation circuit device suitable for use in a frequency conversion unit that performs frequency conversion on a radio transmission signal having a relatively high carrier frequency to obtain an intermediate frequency signal of a predetermined frequency.

[0008]

An oscillating circuit device according to the present invention comprises: an oscillating circuit forming portion including an active element for oscillation; and an LC resonance circuit forming portion connected to the oscillating circuit forming portion. Under the condition that the LC resonance circuit forming section is configured to include the capacitive element arranged on the wiring board and the inductive element formed by the pattern conductor provided on the surface of the wiring board, A void portion penetrating the wiring board is formed in the vicinity.

In the oscillation circuit device according to the present invention thus configured, the inductive element that forms the LC resonance circuit forming portion together with the capacitive element disposed on the wiring board is a wiring in which the capacitive element is disposed. Since it is formed by the pattern conductor provided on the surface of the substrate, it is not necessary to use an air-core coil as a component of the LC resonance circuit forming portion, and therefore, an air-core coil resulting from the use of the air-core coil It is possible to avoid the disadvantage that the cost including the cost required for the mounting work on the printed wiring board and the adjustment work after mounting the air-core coil on the printed wiring board is increased.

In addition, a void is formed in the wiring board provided with the pattern conductor forming the inductive element which forms the LC resonance circuit forming portion together with the capacitive element in the vicinity of the pattern conductor, thereby forming a gap. A decrease in the dielectric constant between the pattern conductor and the ground potential point is caused, and the unnecessary capacitance formed between the pattern conductor and the ground potential point is effectively reduced. Thereby,
When the inductive element forming the LC resonance circuit forming section together with the capacitive element is formed by the pattern conductor provided on the surface of the wiring board, the resonance circuit formed by the LC resonance circuit forming section has the resonance frequency. Can have a relatively wide variable range in a relatively high frequency range, and as a result, the oscillation circuit device according to the present invention including such an LC resonance circuit forming section has a relatively high oscillation frequency. A frequency conversion unit that can obtain a relatively wide variable range in a region, performs frequency conversion on a received radio transmission signal having a relatively high carrier frequency, and obtains an intermediate frequency signal of a predetermined frequency set in advance. It is preferable to be used for.

[0011]

1 and 2 show an example of an oscillation circuit device according to the present invention. In this example, an oscillation circuit forming portion 12, a pair of capacitors 13 and 14, which are a pair of capacitance elements, and a pair of variable capacitance elements are arranged on a printed wiring board 11 provided with a printed wiring composed of a pattern conductor on at least one surface. It is configured to include certain variable capacitance diodes 15 and 16 and a pattern conductor 17 provided on the printed wiring board 11 forming an inductive element.

The oscillation circuit forming section 12 is an integrated circuit (IC)
The component includes, for example, an active oscillation element, which is a transistor. The pattern conductor 17 is formed in a band shape and extends linearly. One end of the pattern conductor 17 is connected to one end of the variable capacitance diode 15 via a connection pattern conductor 18, and the other end is connected to the connection pattern conductor. 1
9, one end of the variable capacitance diode 16 is connected. The other end of the variable capacitance diode 15 is connected to the connection pattern conductor 20, the capacitor 13, and the connection pattern conductor 2.
1, the other end of the variable capacitance diode 16 is connected to the connection pattern conductor 22, the capacitor 14, and the connection pattern conductor 23.
Are connected to the oscillation circuit forming section 12 via the.

The capacitor 13, the variable capacitance diode 15, the pattern conductor 17 forming an inductive element, the variable capacitance diode 16 and the capacitor 14 constitute an LC resonance circuit forming unit 24 connected to the oscillation circuit forming unit 12. ing.

An oscillation circuit forming section 12 is provided and L
In the printed wiring board 11 provided with the C resonance circuit forming part 24, a void penetrating therethrough is formed in the vicinity of the pattern conductor 17 in the form of a pair of through holes 25 and 26. These through-holes 25 and 26 extend along the pattern conductor 17 which extends in a strip shape, respectively.
It is arranged on both sides of the pattern conductor 17.

As described above, the through holes 25 and 26 extending along the pattern conductor 17 are formed on the printed wiring board 11 in the vicinity of the pattern conductor 17 on both sides of the pattern conductor 17, that is, with the pattern conductor 17 interposed therebetween. As a result, the volume of the printed wiring board 11 acting as a dielectric, which is to be disposed between the pattern conductor 17 and the ground potential point, is reduced. The dielectric constant is reduced so as to approach the dielectric constant of air. Therefore, unnecessary capacitance between the pattern conductor 17 and the ground potential point can be effectively reduced.

FIG. 3 shows an equivalent circuit representing an example of the oscillation circuit device according to the present invention shown in FIGS. In this equivalent circuit, the oscillation circuit forming section 12 includes a pair of NPN transistors 30 and 31 which are active elements for oscillation. A capacitor 32 is connected between the base and the emitter of the transistor 30.
Further, a capacitor 33 is connected between the base and the emitter of the transistor 31. The collectors of the transistors 30 and 31 are connected to the ground potential point, and the emitter of the transistor 30 and the transistor 3
The capacitor 34 is connected between the first emitter and the first emitter.

The stray capacitance existing between the base and the emitter of the transistor 30 is represented by the capacitor 35, and the stray capacitance existing between the collector and the emitter of the transistor 30 is represented by the capacitor 36.
Further, the stray capacitance that will be present between the base and the collector of the transistor 30 is represented by the capacitor 43. Further, a stray capacitance that is to be present between the base and the emitter of the transistor 31 is represented by the capacitor 37, and a stray capacitance that is to be present between the collector and the emitter of the transistor 31 is represented by the capacitor 38.
Further, the stray capacitance that will be present between the base and the collector of the transistor 31 is represented by the capacitor 44.

The LC resonance circuit forming section 24 is connected between the base of the transistor 30 and the base of the transistor 31 in the oscillation circuit forming section 12 via the terminals 39 and 40, thereby forming the LC resonance circuit forming section. The part 24 is
A capacitor 13, a variable capacitance diode 15, an inductive element formed by the pattern conductor 17, a variable capacitance diode 16, and a capacitor 14 are connected in series.
The stray capacitance existing between the pattern conductor 17 and the ground potential point is represented by the capacitors 41 and 42.

In one example of the oscillation circuit device according to the present invention, which is represented by such an equivalent circuit, the LC resonance circuit forming section 24 is connected to the pattern conductor 17 represented by the capacitor 41 and the ground potential during an actual operation. And the capacitors 32, 33, and 34 included in the oscillation circuit forming unit 12.
And the capacitors 35 and 3 in the oscillation circuit forming section 12.
6, 37, 38, 43, and 44 to form an integrated LC parallel resonance circuit that is a resonance circuit including a stray capacitance represented by. Such an integrated LC parallel resonance circuit is as shown in FIG. 4, and includes a variable capacitance diode 15, a capacitor 13, a parallel connection of capacitors 32 and 35, a capacitor 34, a capacitor 33 and a capacitor 37.
, A series connection of the capacitor 14 and the variable capacitance diode 16, a series connection of the capacitor 41 and the capacitor 42 connected in parallel to the series connection, and a connection point between the capacitor 41 and the capacitor 42 and the capacitor. A capacitor 36 connected between one end of the capacitor 34 and a capacitor 38 connected between a connection point between the capacitor 41 and the capacitor 42 and the other end of the capacitor 34, and a connection between the capacitor 41 and the capacitor 42 A capacitor 43 connected between a point and one end of the capacitor 13, and a capacitor 4 connected between a connection point between the capacitors 41 and 42 and one end of the capacitor 14.
4 forms a capacitance portion, and the pattern conductor 17 is connected to the capacitance portion in parallel to form an induction portion.

In this integrated LC parallel resonance circuit, the capacitors 41 and 42 represent the stray capacitance existing between the pattern conductor 17 and the ground potential point. 1 and 2, as shown in FIGS. 1 and 2, through holes 25 and 26 extending along the pattern conductor 17 are formed near the pattern conductor 17 on the printed wiring board 11. By being formed on both sides of the pattern conductor 17, it can be effectively reduced,
The capacitors 41 and 42 correspond to capacitors having extremely small capacitance values.

In the integrated LC parallel resonance circuit, the resonance frequency changes according to the change in the capacitance value of each of the variable capacitance diodes 15 and 16, and the capacitance value of each of the variable capacitance diodes 15 and 16 changes. Is relatively small to obtain a relatively high resonance frequency, the capacitor 41
And 42 correspond to capacitors having very small capacitance values, so that capacitors 41 and 42
It is unlikely that the effect that the capacitance value of the variable capacitance diodes 15 and 16 is reduced substantially will not be reflected. That is, when the capacitance values of the variable capacitance diodes 15 and 16 are relatively small, the effect is sufficiently reflected, and a relatively high resonance frequency can be obtained reliably. Therefore, the integrated LC
The parallel resonance circuit uses the printed wiring board 1 without using the air-core coil.
The resonance frequency of the inductive element formed by the pattern conductor 17 provided on the variable capacitance diode 15 is changed to a relatively wide variable range in a relatively high frequency region in accordance with a change in the capacitance value of the variable capacitance diodes 15 and 16. It can be said that it has.

In the integrated LC parallel resonance circuit shown in FIG. 4, the resonance frequency is composed of the oscillation circuit forming section 12 and the LC resonance circuit forming section 24 represented by the equivalent circuit shown in FIG. Oscillation circuit device,
The oscillation frequency in the example of the oscillation circuit device according to the present invention shown in FIGS. 1 and 2 is determined. Under such circumstances, as described above, the resonance frequency of the integrated LC parallel resonance circuit can have a relatively wide variable range in a relatively high frequency range, and thus the present invention shown in FIGS. An example of the oscillator circuit device according to the present invention is that the oscillation frequency can have a relatively wide variable range in a relatively high frequency range, and therefore, the received radio transmission signal having a relatively high carrier frequency has a high frequency. It is suitable for use in a frequency conversion unit that performs conversion to obtain an intermediate frequency signal of a predetermined frequency set in advance.

In the above example, the gap formed in the vicinity of the pattern conductor 17 on the printed wiring board 11 is obtained by the pair of through holes 25 and 26 extending along the pattern conductor 17. However, in the oscillation circuit device according to the present invention, the gap formed in the vicinity of the pattern conductor on the printed wiring board is limited to such an example in number, shape, arrangement, and the like. Instead, it may be obtained by various through-holes, notches, and the like provided in the vicinity of the pattern conductor on the printed wiring board.

[0024]

As is apparent from the above description, in the oscillation circuit device according to the present invention, the LC resonance circuit forming portion connected to the oscillation circuit forming portion is formed together with the capacitance element arranged on the wiring board. Since the inductive element to be formed is formed by the pattern conductor provided on the surface of the wiring board on which the capacitive element is disposed, it is not necessary to use an air-core coil as a component of the LC resonance circuit forming portion. Therefore, according to the oscillation circuit device according to the present invention, due to the use of the air-core coil,
It is possible to avoid the inconvenience of increasing the cost including the cost required for the work of attaching the air-core coil to the printed wiring board and the adjustment work after attaching the air-core coil to the printed wiring board.

Further, in the oscillation circuit device according to the present invention, the LC resonance circuit forming portion is formed on the wiring board provided with the pattern conductor forming the inductive element constituting the capacitive element together with the capacitive element in the vicinity of the pattern conductor. The formation of the penetrating gap causes a decrease in the dielectric constant between the pattern conductor and the ground potential point, and effectively reduces unnecessary capacitance formed between the pattern conductor and the ground potential point. It can be reduced. Thereby, the resonance circuit formed by the LC resonance circuit forming section is based on the fact that the inductive element forming the LC resonance circuit forming section together with the capacitive element is formed by the pattern conductor provided on the surface of the wiring board. The resonance frequency can take a relatively wide variable range in a relatively high frequency range. As a result, the oscillation circuit device according to the present invention including such an LC resonance circuit forming section has a comparatively large oscillation frequency. It is possible to obtain a relatively wide variable range in a relatively high frequency range, perform frequency conversion on a received radio transmission signal having a relatively high carrier frequency, and set an intermediate frequency signal of a predetermined frequency set in advance. This is suitable for use in a frequency conversion unit that obtains

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of an oscillation circuit device according to the present invention.

FIG. 2 is a side view of the example shown in FIG. 1 including a partially broken cross section.

FIG. 3 is a circuit diagram showing an equivalent circuit of one example of the oscillation circuit device according to the present invention shown in FIGS. 1 and 2;

FIG. 4 is a circuit diagram showing an equivalent circuit representing a resonance circuit formed in the example of the oscillation circuit device according to the present invention shown in FIGS. 1 and 2;

[Explanation of symbols]

11 Printed wiring board 12 Oscillation circuit forming part
13, 14, 32, 33, 34, 35, 36, 37, 3
8, 41, 42, 43, 44 Capacitor 15, 16 Variable capacitance diode 17 Pattern conductor 18, 19, 20, 21, 22, 23 Pattern conductor for connection 24 LC resonance circuit forming part 25, 26 Through hole 30, 31 Transistor

Claims (7)

[Claims] An oscillation circuit forming section including an active element for oscillation and an LC resonance circuit forming section connected to the oscillation circuit forming section, wherein the LC resonance circuit forming section is arranged on a wiring board. It is configured to include a capacitive element and an inductive element formed by a pattern conductor provided on the surface of the wiring board, and a void portion penetrating the wiring board is formed in a portion of the wiring board near the pattern conductor. An oscillation circuit device characterized by the above-mentioned. 2. An inductive element included in an LC resonance circuit forming portion is formed by a band-shaped extending pattern conductor provided on a surface of a wiring board, and a gap in the wiring board is formed along the band-shaped extending pattern conductor. 2. The oscillation circuit device according to claim 1, wherein the oscillation circuit device is formed by an elongated through hole. 3. The oscillation circuit device according to claim 2, wherein through holes extending along a strip-shaped pattern conductor provided on the surface of the wiring board are formed on both sides of the pattern conductor. 4. The variable capacitance element included in the LC resonance circuit forming part is a variable capacitance element, and the oscillation frequency in the oscillation circuit forming part changes according to a change in the capacitance of the variable capacitance element. 2. The oscillation circuit device according to 1. 5. The oscillation circuit device according to claim 4, wherein the variable capacitance element included in the LC resonance circuit forming section is a variable capacitance diode. 6. An LC resonance circuit forming portion includes an inductive element formed by a strip-shaped pattern conductor provided on a surface of a wiring board, and two variable capacitance diodes having one end connected to both ends of the pattern conductor, respectively. And comprising
6. The oscillation circuit device according to claim 5, wherein the other end of each of the two variable capacitance diodes is connected to an oscillation circuit forming portion via a capacitance element. 7. The oscillation device according to claim 1, wherein the oscillation circuit forming portion is disposed on a wiring board provided with a capacitive element and an inductive element constituting the LC resonance circuit forming portion. Circuit device.