JPS63138805A - Microwave oscillator - Google Patents

Abstract

PURPOSE:To realize a broad band microwave oscillator by inserting a phase shifter in a line so as to make the phase shift quantity variable in response to the microwave oscillating frequency. CONSTITUTION:A resonator 14, a 1st line 11 coupled with the resonator 14, a transistor (TR) 13 whose 1st terminal 13B is connected to one end of the line 11 and a 2nd line 12 whose one end is connected to 2nd terminal 13E of the TR 15 form the microwave oscillator. In this case, the phase shifter 31 whose phase shift quantity is variable in response to the microwave oscillation frequency is inserted in series with at least one of the lines 11 and 12. The resonator 14 is adjusted to set the oscillating frequency f0 in an optional value. In this case, the phase shift quantity of the phase shifter 31 is changed in interlocking with the adjustment. Then an optimum phase condition is obtained with an optional oscillating frequency f0. Thus, a broad band microwave oscillator is realized.

Description

[Detailed Description of the Invention] [Summary] A microwave oscillator comprising a first line and a second line provided with a transistor sandwiched therebetween, and a resonator coupled to the first line, the microwave oscillator comprising: a resonator coupled to the first line; By inserting a phase shifter and making the amount of phase shift variable according to the microwave oscillation frequency, a broadband micro oscillator is realized.

[Industrial application field]

The present invention relates to microwave oscillators.

Microwave oscillators are, for example, G, 5GIIz, 1
It generates microwaves such as 3Gllz, and is an essential element for microwave communications, such as satellite communications.

Conventional microwave oscillators are designed to provide maximum microwave output at a specific frequency. However, according to recent trends, there is a demand for increasing the range of the specific frequency and obtaining the maximum microwave output not only at the specific frequency but also at all nearby frequencies. In other words, the microwave oscillator has a wider band.

[Conventional technology]

FIG. 7 is a configuration diagram showing an example of a conventional microwave oscillator. Furthermore, FIG. 8 is a configuration diagram showing an example of a conventional microwave oscillator that also has a multiplication function.

Common components in both figures are designated with the same reference numbers or symbols. Therefore, the microwave oscillator 10
and 20 are an output line 18 and a bandpass filter (consisting of multistage microstrip lines) 19, respectively.
They differ only in that they have . Note that what is sent out from the output terminal 17 is the original oscillation output OUT in the oscillator 10, and the multiplied oscillation output OUT in the oscillator 20.
It is UT'. However, the present invention is applicable to any oscillator (10
, 20).

In FIGS. 7 and 8, 11 is a first line, 12 is a second line, and a transistor 13 is connected to one end of each of these lines.
The corresponding terminals of the terminals are connected. Furthermore, a resonator 14 is coupled to the first line 11 . Generally, an absorption resistor 15 and a bias cut capacitor 16 are connected to the other end of the first line 11.

The transistor 13 has a base 13B and an emitter 13E as a first terminal and a second terminal, respectively, and a collector 13C, which is a third terminal, is usually directly connected to a conductive substrate. Note that the transistor 13 may be a field effect transistor (FET), and in this case, the transistor 13 may be a field effect transistor (FET). The second and third terminals serve as the gate, drain, and source, respectively. When the transistor 13 is a normal bipolar transistor, the first line 11 and the second line 12 form a base line and an emitter line, respectively. These are microstrip lines.

In the oscillator 10, an output line 18 made of a microstrip line is connected to a resonator 14, which is a dielectric resonator, for example.
magnetically coupled with the frequency f. Microwave oscillation output (
Source oscillation output) OUT is sent. On the other hand, in the oscillator 20, a filter 19 having a passband of 2fo sends out a multiplied oscillation output OUT' with a frequency of 2'.

Now, if we pay attention to the oscillator lO in FIG.
The reflection coefficient when looking at the transistor 13 side from the boundary with 1 is r
6. If the reflection coefficient looking at the first line 11 side is rL, then the oscillation conditions are that lr'a l ・lrt l≧1 holds for the amplitude, and lra + lrL 2βt,, = 2nπ holds for the phase. . However, Ll is the length clearly shown in FIG. 7, β is a phase constant, and □ is a natural number. When viewed from the above formula, especially the phase-related formula, the length Ll is one of the important parameters that determines the oscillation conditions.

On the other hand, regarding the oscillator 20 in FIG. 8, the length L2 in the figure is uniquely determined under a certain phase condition. That is, when obtaining the multiplied oscillation output of 2fo mentioned above,
The phase when the microwave from the transistor 13 is reflected by the bandpass filter 19 and returns again must be a phase convenient for converting the original oscillation output (frequency fo) to twice the frequency. , the phase at this time has length L
It is determined based on 2. After all, the length 1.1 is one of the important parameters that determines the conditions for multiplied oscillation.

[Problem that the invention seeks to solve]

As mentioned above, in order to obtain the maximum level of the oscillation output (OUT, OUT'), increase the length of the line.

Lx) is an important parameter. Conversely,
Once the length of the line is determined, the frequency of the oscillation output is determined accordingly.

However, as mentioned above, as a recent trend, there has been a demand to obtain oscillation outputs of different frequencies from one microwave oscillator at their respective maximum levels. This is because, for example, there is an advantage that a single type of microwave oscillator can supply multiple types of microwave oscillation outputs.

However, with conventional microwave oscillators, it is difficult to supply multiple types of microwave oscillation output with a single type of microwave oscillator, so it is necessary to have an optimal design for each, that is, an optimal length or L2 There is a problem in that a microwave oscillator designed to have this must be prepared individually.

[Means for solving problems]

FIG. 1 is a diagram showing the principle configuration of a microwave oscillator based on the present invention. However, similar components to those already mentioned include:
Indicated by the same reference number or symbol. Therefore, the components indicated with reference numbers 31 and 41, ie the phase shifter, are new components. The microwave oscillator 30 shown in FIG. 7A has a phase shifter 31 inserted into the first line 11, and can be applied to the oscillator 10 shown in FIG. The microwave oscillator 40 shown in FIG. 8B has a phase shifter 41 inserted into the second line 12, and can be applied to the oscillator 20 shown in FIG. Furthermore, if necessary, phase shifters may be inserted into both the first line 11 and the second line 12, respectively. This is the main figure (
C) is the microwave oscillator 50.

[For production]

First, in the case of the microwave oscillator 30, the resonator 14 is adjusted (described later) to obtain the oscillation frequency r. Set to any value. At this time, the amount of phase shift of the phase shifter 31 is changed in conjunction with the adjustment. Then, the arbitrary oscillation frequency f. Optimal phase conditions can be obtained later. In other words, maximum oscillation output can be obtained. -In particular, the length Ll in Figure 7 has a proportional relationship with the wavelength λ (
For example, since L1=-λ), when the wavelength λ should be shortened (or lengthened), the oscillation frequency r0 should be further increased (
When it should be (or lower) it should be longer, and when it should be shorter (or longer). That is, the amount of phase shift by the phase shifter 31 is made small (or large). In short, the oscillation frequency f.

A phase shifter is determined to interpolate the deviation of the phase shifter.

Next, in the case of the microwave oscillator 40, it is convenient to have a multiplication function, but for example, when the frequency of the original oscillation output to be doubled changes, conventionally, it is convenient to have a multiplication function. The length of the second line 12 was adjusted to match the phase. In the present invention, this convenient phase is created by the phase shifter 4I.

The microwave oscillator 50 has both phase shifters 31 and 41, and can extract both the oscillation output and the multiplied oscillation output over a wide band. In any case, by inserting a variable phase shifter into at least one of the first line 11 and the second line 12, a broadband microwave oscillator is realized.

〔Example〕

FIG. 2 is a diagram showing a first example of a microwave oscillator according to the present invention. This microwave oscillator 60 corresponds to the microwave oscillator 10 of FIG. 7 to which the phase shifter 31 according to the present invention is applied. In this example, original oscillation outputs OUT having various oscillation frequencies (f01 to fax) that can always maintain the maximum level are obtained. However, lfo+f
ozl is 13GII using a dielectric resonator 14, for example.
When oscillating on the order of □, it is about several hundred MHz.

FIG. 3 is a sectional view showing a specific example of a dielectric resonator.

The dielectric resonator 14 has a housing 6 that serves as an electromagnetic shield.
1, a metal screw 62 that engages with the metal screw 62, a ferroelectric material (for example, barium titanate) 64 provided facing the metal plate 63 on the head part at a distance d, and It consists of a spacer (for example, quartz) 65 for installation on top. Oscillation frequency f of microwave oscillator
In order to change 0, the distance d can be changed by turning the screw 62.

On the other hand, as the phase shifter 31 (the same applies to the phase shifter 41), for example, a variable capacitance diode (varactor diode) can be used, and by controlling its bias voltage,
A desired amount of phase shift can be given to the phase of the microwave on the first line 11 (the same applies to the second line 12). In the present invention, since the amount of phase shift is made variable according to the oscillation frequency, for example, the bias voltage of the variable capacitance diode can be changed in response to raising and lowering the screw 62 of the resonator 14 shown in FIG. good. - For example, it is possible to provide a sliding resistor that interlocks with the top and bottom of the screw 62, generate a variable voltage via this sliding resistor, and use this variable voltage as the bias voltage.

FIG. 4 is a diagram showing a second example of a microwave oscillator according to the present invention. This microwave oscillator 70 corresponds to the microwave oscillator 20 of FIG. 8 to which a phase shifter 41 according to the present invention is applied.

FIG. 5 is a perspective view showing an example of the configuration of the microwave oscillator 70. Components similar to those already described are indicated by the same reference numerals or symbols, and the housing (electromagnetic shield) is shown with the lid opened and turned over in this figure. The detailed inside of the housing is shown in FIG. 6.

In FIG. 5, a housing 71 is a larger version of the housing 61 in FIG. 3. Its lid is marked 72,
! ! The previously described screw 62 and plate 63 are held by 72. The previously described ferroelectric material 64 is visible within the housing 71, and furthermore, parts of two ceramic substrates 73 and 74 separated by the transistor portion are visible.

The multiplied oscillation signal is taken out by a coaxial cable 76 via an output connector 75.

6 is a plan view of the inside of the housing 71 in FIG. 5. FIG. The newly shown components in this figure are, for example, 1
Filters 81 and 83 that prevent 3Gtlz microwaves from being grounded, and chip capacitors 82 and 84
and high impedance lines 85 and 86. B is a bias voltage source for the transistor, and 2 is an emitter voltage source for the transistor, which are led from outside the housing by a lead wire. A variable bias voltage source Vl is connected to the variable capacitance diode 41 forming the phase shifter. The accompanying components 91, 92, 95 are the aforementioned 81
, 82 and 85, respectively. In addition, G in the figure
indicates the part that is welded to the side wall of the housing and is grounded here.

77 is the bottom surface of the housing 71 and serves as a conductor substrate, and the transistor 13 is directly screwed to the collector thereof.

〔Effect of the invention〕

As described in detail above, according to the present invention, a microwave oscillator is realized in which the maximum output level can be obtained at various oscillation frequencies through simple bias voltage control without adjusting the line length.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the principle configuration of a microwave oscillator according to the present invention, FIG. 2 is a diagram showing a first example of a microwave oscillator according to the present invention, and FIG. 3 is a cross-sectional view showing an example of a dielectric resonator integrated body. , FIG. 4 is a diagram showing a second example of the microwave oscillator according to the present invention, FIG. 5 is a perspective view showing an example of the configuration of the microwave oscillator 70, and FIG. 6 is a plane inside the housing 71 in FIG. 5. 7 is a diagram showing an example of a conventional microwave oscillator, and FIG. 8 is a configuration diagram showing an example of a conventional microwave oscillator that also has a multiplication function. 11...First track, 12...Second track, 13
...transistor, 13B...first terminal, 13E
...Second terminal, 14...Resonator, 30, 4
0, 50...Microwave oscillator, 31, 41...
・Phase shifter.

Claims (1)

[Claims] 1. A resonator (14), a first line (11) coupled to the resonator (14), and a first terminal (13B) connected to one end of the first line (11). In the microwave oscillator, the microwave oscillator includes a transistor (13), and a second line (12), one end of which is connected to a second terminal (13E) of the transistor (13). is a variable phase shifter (
31, 41) are inserted in series into at least one of the first line (11) and the second line (12).