JPH02284507A - Oscillator for radio communication equipment - Google Patents

Abstract

PURPOSE:To reduce the cost of an oscillator and to miniaturize the oscillator by providing a carrier oscillator which is connected to a first opening end surface and oscillates a carrier signal whose frequency is decided by means of a dielectric coaxial resonator, and a local oscillator which is connected to a second opening end surface and oscillates a local oscillation signal whose frequency is decided by means of the dielectric coaxial resonator. CONSTITUTION:At the time of transmission, a control voltage VC1 is impressed on a control terminal 7 and the frequency of a carrier is changed. Then, a modulation signal is inputted to a modulation terminal 6, and the carrier signal is modulated. Next, a switching voltage VS is impressed on a switching terminal 17. Thus, a transistor 15 is turned on, and a transistor 16 is turned off. At the time of reception, a control voltage VC2 is impressed on a control terminal 13, and the frequency of the local oscillation signal is changed. Consequently, the transistor 15 is turned off and the transistor 16 is turned on. Thus, one resonator 24 is shared at the time of transmission and reception by connecting the carrier oscillator 1 and the local oscillator 8 to the opening end surfaces 241 and 242 of a lambda/2 type resonator.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to an oscillator for a wireless communication device that includes a carrier wave oscillator and a local oscillator, each of which has an oscillation frequency determined by a dielectric coaxial resonator.

"Prior Art" FIG. 5 is a block diagram showing an example of the configuration of a conventional oscillator for a wireless communication device. In this figure, 1 is a carrier wave oscillator that oscillates a carrier wave signal for transmission, modulates the carrier wave signal with a modulation signal, and outputs it, 2 is a transistor for high frequency oscillation, and 3 is an LC resonant circuit. This is a λ/4 type dielectric coaxial resonator (hereinafter simply referred to as a resonator) corresponding to an inductor. Here, the structure of the resonator 3 is shown in FIG.

In this figure, 3. is an open end surface, 3. is the shorted end face. Note that a λ/2 type resonator shown in FIG. 7 may also be used as the resonator 3. In FIG. 7, 33 and 34 are open end surfaces, respectively.

Further, in FIG. 5, 4 is a variable capacitance diode whose junction capacitance is varied depending on the applied voltage, 5 is a variable capacitance diode whose bm is connected to the collector of the transistor 2, and the other end is the open end face 3 of the resonator 3. 6 is a modulation terminal to which a modulation signal S) I is input, and 7 is a control terminal to which a control voltage V (1) is applied to control the frequency of the carrier wave.

Furthermore, 8 is a local oscillator that outputs a local oscillation signal for reception, 9 is a transistor, 10 is a resonator, 10. and 102 are an open end face and a shorted end face of the resonator 10, 11 is a variable capacitance diode, 12 is a capacitor,
13 is the control voltage ■. , is the control terminal to which is applied. This local oscillator 8 has the same structure and operation as the carrier wave oscillator 1 except that the carrier wave oscillator 1 outputs a modulated carrier wave signal, whereas the local oscillator 8 outputs a local oscillation signal with a frequency different from that of the carrier wave. The same is true.

In addition, 14 is a switching circuit that outputs a carrier wave signal or a local oscillation signal by being switched by a switching voltage 8 during transmission and reception, 15 and 16 are transistors for switching, and 17 is applied with a switching voltage V5. The switching terminal 18 is an output terminal from which a carrier signal or a local oscillation signal is output. Incidentally, this output signal is input to a not-shown amplifier 7.

Further, FIG. 8 shows the mounting state of the resonators 3 and 10.

In this figure, parts corresponding to those in FIG. 5 are given the same reference numerals, and their explanations will be omitted. In this diagram,
19 is a printed circuit board provided with holes for taking out resonators 3 and 10, 20 and 21 are ground electrodes provided on both sides of the two consecutive holes, and 22 and 23 are resonators 3 and 10, respectively. each outer conductor and ground electrode 2
This is a node that electrically connects 0 and 21.

In such a configuration, during transmission, a control voltage VCI is applied to the control terminal 7 to vary the carrier wave frequency, and a modulation signal SM is input to the modulation terminal 6 to modulate the carrier wave signal. Further, a switching voltage V8 is applied to the switching terminal 17. As a result, the transistor 15 is turned on, the transistor 16 is turned off, and the carrier wave signal modulated by the modulation signal is output from the output terminal 18, and No. 1 (not shown) is output. input to the amplifier.

Furthermore, during reception, a control voltage (1.2) is applied to the control terminal 13 to vary the frequency of the local oscillation signal.

At this time, the switching voltage Vs is not applied to the switching terminal 17.

Therefore, the trans/metal 15 is turned off and the transistor 1G is turned on, so that a local oscillation signal is outputted from the output terminal 18 and inputted to the knob and Nopha amplifier (not shown).

"Problem to be Solved by the Invention" By the way, the above-mentioned conventional oscillator for wireless communication equipment has the disadvantage that it is expensive because the resonators 3 and 10 are used for the carrier wave oscillator 1 and the local oscillator 8, respectively. Ta.

Furthermore, in the case of using a λ/2 type resonator 3 (2-), which is not shown in FIG. 7, there is a drawback that a larger space is required on the printed circuit board 19 than in the above-mentioned case. Therefore, there is a problem in that miniaturization and high-density packaging are difficult.

Furthermore, as shown in FIG. 8, when two λ//l type resonators 3 and 10 are used, the printed circuit board 19'' is smaller than when two λ/2 type resonators are used. The effective area on which circuit components can be placed is wide. However, a λ/4 type resonator has a lower Q at no load than a λ/2 type resonator, so if this is used for carrier wave oscillator 1 and local oscillator 8, the outputs of transistors 2 and 9 will be lower. The oscillation of each oscillator becomes unstable due to the influence of changes in impedance. subordinate
9, the C/N ratio of the carrier wave signal or local oscillation signal outputted from the terminal 18 deteriorates.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide an oscillator for a radio communication device that can be made low in price and small in size, and can output a signal with a good C/N ratio.

"Means for Solving the Problem" An oscillator for a wireless communication device according to the present invention has a first and a second oscillator.
a 1/2 wavelength type dielectric coaxial resonator having an open end surface; a carrier wave oscillator connected to the first open end surface and oscillating a carrier signal whose frequency is determined by the dielectric coaxial resonator; It is characterized by comprising a local oscillator connected to the end face and oscillating a local oscillation signal whose frequency is determined by the dielectric coaxial resonator.

"Operation" According to this invention, the carrier wave oscillator and the local oscillator
Two long-length dielectric coaxial resonators are shared, and a carrier wave signal and a local oscillation signal whose frequencies are determined by the dielectric coaxial resonators are respectively oscillated.

Embodiment J An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram showing the configuration of an oscillator for a wireless communication device according to an embodiment of the present invention. The same reference numerals are given to the parts corresponding to each part in Fig. 5, and the explanation thereof is omitted.
．． is connected to one end of the capacitor 5, and the open end surface 242 is connected to one end of the capacitor 12.
4 has been newly established. In addition, the resonator 24 is shown in FIG.
Indicates the implementation status of In this figure, Figures 1 and 8
Components corresponding to those in the figures are given the same reference numerals, and their explanations will be omitted. In this figure, 25 is the printed circuit board 1
Ground electrodes 26 are provided on both sides of the hole for attaching the resonator 24 provided in the second hole, and 26 is a hang that electrically connects the outer conductor of the resonator 24 and the ground electrode 25.

In such a configuration, during transmission, a control voltage VCI is applied to the control terminal 7 to vary the frequency of the carrier wave, and a modulation signal is input to the modulation terminal 6 to modulate the carrier wave signal. Further, a switching voltage v8 is applied to the switching terminal 17.

As a result, transistor 5 is turned on and transistor 16 is turned off.

The equivalent circuit of FIG. 1 in this case is shown in FIG. In FIG. 3, 27 is a composite capacitance on the local oscillator 8 side. Therefore, a carrier signal modulated by the modulation signal is output from the output terminal 18 and input to a buffer amplifier (not shown).

Also, during reception, a control voltage ■ is applied to the control terminal 13. , to vary the frequency of the local oscillation signal.

At this time, the switching voltage V5 is not applied to the switching terminal 17.

Therefore, transistor 15 is turned off and transistor 16 is turned on. The equivalent circuit of FIG. 1 in this case is shown in FIG. In FIG. 4, 28 is a composite capacitance on the carrier wave oscillator 1 side. Therefore, a local oscillation signal is output from the output terminal 18 and input to a buffer amplifier (not shown).

- As explained above, the open end face 24. of the λ/2 type resonator 24. and 24. A carrier wave oscillator l and a local oscillator 8 are connected to each, so that one resonator 24 is shared during transmission and reception, so that the conventional λ/
Compared to the case of using two 4-type or λ/2-type resonators, material costs and processing costs for the printed circuit board 19 are reduced゛C
Wear.

Furthermore, compared to the case where two λ/4 type resonators are used, less space is required for installation. This is because, although the occupied area of the resonator itself is the same as in the conventional case, in the conventional case, the wasted space caused by separating the two λ/4 type resonators and the outer conductor of each are This is because the ground electrodes 20 and 21 are required to be grounded.

Therefore, since the effective area of the printed circuit board 19 becomes larger,
High-density packaging is possible, and the circuit can be miniaturized.

Furthermore, since a λ/2 type resonator with a high Q at no-load is used, the oscillation of each oscillator is stabilized, and the C/N ratio of the signal output from the output terminal 18 is improved.

"Effects of the Invention" As explained above, according to the present invention, only one dielectric coaxial resonator is required, so there is an effect that the structure can be constructed at low cost. Moreover, it has the effect of being able to be made smaller. In addition,
Since a λ/2 type dielectric coaxial resonator is used, the output signal has a good C/N ratio.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing the configuration of an oscillator for a wireless communication device according to an embodiment of the present invention, FIG. 2 is a diagram showing the mounting state of the dielectric coaxial resonator 24, and FIG. 3 is a diagram showing the state of the transmission shown in FIG. 4 is an equivalent circuit diagram at the time of reception in FIG. FIG. 8 is a diagram showing the structure of dielectric coaxial resonators 3 and 9 of type 4 and λ/2, and FIG. 8 is a diagram showing the mounting state of dielectric coaxial resonators 3 and 10. ■ ・Carrier wave oscillator, ・・local oscillator, dielectric coaxial resonator.

Claims (1)

[Claims] a 1/2 wavelength dielectric coaxial resonator having first and second open end surfaces, and a carrier wave that is connected to the first open end surface and that oscillates a carrier signal whose frequency is determined by the dielectric coaxial resonator. An oscillator for a wireless communication device, comprising: an oscillator; and a local oscillator that is connected to the second open end surface and that oscillates a local oscillation signal whose frequency is determined by the dielectric coaxial resonator.