JPH03182104A - Tuning type oscillator - Google Patents

Abstract

PURPOSE:To suppress the temperature change of an oscillation frequency over a wide temperature range by constituting the oscillator of a first tuning type oscillating element, second tuning type oscillating element and mixer, as elements equipped with three fundamental functions. CONSTITUTION:First and second tuning type oscillating elements 12 and 13 respectively output oscillation signals so that the absolute value of difference between the oscillation frequency at a specified temperature and the oscillation frequency at an arbitrary temperature can be equal and that the code of this difference can obtain a reverse relation. A mixer 17 mixes the first oscillation signal outputted form the first tuning type oscillating element 12 and the second oscillation signal outputted from the second tuning type oscillating element 13 and generates an oscillation output signal with the frequency of a sum for the frequency of the first oscillation signal and the frequency of the second oscillation signal. Thus, a tuning type oscillator can be obtained while reducing the temperature change of the oscillation frequency over the wide temperature range.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a tunable token vibrator that generates microwaves, for example.

[Conventional technology]

Conventionally, as this type of synchronized keepsake, there has been one as shown in FIG. This figure 5 is by Nakano et al.'13
It is based on the configuration shown in ``GHz Band YIG Thin Film Tuned Oscillator'' (1988 Institute of Electronics, Information and Communication Engineers Spring National Conference, C671), where 1 is a yoke, 2 is a coil, 3 is a permanent magnet, 4 is a yoke 1, Coil 2. A magnetic circuit includes a permanent magnet 3, and 5 is a high frequency circuit section. FIG. 6 is a top view of the high frequency circuit 5 shown in FIG. 5, where 6 is a ferrimagnetic thin film resonator, and 7 is a dielectric substrate used to manufacture and hold the ferrimagnetic thin film 6. , 8 is an active element such as an FET (Li field effect transistor), 9 is a strip conductor, 10 is a matching circuit composed of the strip conductor 9, 1
1 is a substrate for holding the high frequency circuit section 5;

Next, the operation of this conventional example will be explained.

A magnetic field HO is applied perpendicularly to the film surface by the magnetic circuit 1 to the ferrimagnetic thin film resonator 6, and the resonator resonates at a frequency fT: magnetic resonance expressed by the following equation.

r=r (Ho-N·4πM)...Mountain (1) Here, T is the gyromagnetic ratio, N is the demagnetizing field coefficient, and 4πM is the saturation magnetization amount of the ferrimagnetic thin film. The input impedance locus near the resonance frequency when looking at the ferrimagnetic i1 film resonator 6 from A in FIG. 6 is shown by the Smith diagram in FIG. B in FIG. 7 indicates a resonance point.

At frequencies other than the vicinity of the resonance frequency, the input impedance exists at a position deviated from the resonance point B by a phase angle of 180''.

The complex reflection coefficient converted from the input impedance is r'
Let it be r. Moreover, when the dimensions of the strip conductor 9 of the matching circuit 10 are adjusted so as to satisfy the condition of the zero-order equation in which ra is the complex reflection coefficient viewed from the active element side than A, oscillation starts.

I r rl, I r al? l, Zr r +-
1r a =o-...-+ (For a two-tuned oscillator, the above formula (2) is applied near the required resonance frequency of the ferrimagnetic thin film resonator 6.
The matching circuit 10 is adjusted so as to satisfy the condition, and since the resonant frequency can be varied by the magnetic field Ho, the oscillation frequency can be controlled by Ho.

The temperature characteristics of the oscillation frequency of the tunable oscillator depend on the temperature characteristics of Ho and 4πM, as shown in equation (1).

In the conventional tunable oscillator, 4 of the ferrimagnetic thin film resonators 6
The temperature change of πM is determined by the material and dimensions of the permanent magnet 3.
The temperature change in the oscillation frequency was offset by the temperature change, thereby reducing the temperature change in the oscillation frequency.

[Problem to be solved by the invention]

A conventional tunable oscillator has four ferrimagnetic thin film resonators 6.
H due to the temperature change of πM and the material and dimensions of the permanent magnet 3
Since we were trying to reduce the temperature change in the oscillation frequency by using the temperature change in
There are limits to the selection of materials and dimensions for πM and the permanent magnet 3.

This invention was made to solve the above-mentioned problems, and for example, the amount of temperature change in the saturation magnetization ρ4πM of the ferrimagnetic thin film resonator is significantly different from the amount of temperature change in the magnetic field Ho caused by the permanent magnet. The object of the present invention is to obtain a tunable oscillator in which the oscillation frequency changes little with temperature over a wide temperature range.

[Means to solve the problem]

The tunable oscillator according to the present invention has a first oscillator that generates oscillation signals in which the absolute value of the difference between the oscillation frequency at a specific temperature and the oscillation frequency at an arbitrary temperature is equal and the sign of the difference is opposite. Second tunable oscillation element 12.
13, the first oscillation signal output from the first tunable oscillation element 12 and the second oscillation signal output from the second tunable oscillation element 13 are mixed to produce a first oscillation signal. The second oscillation signal has a mixer 17 that generates an oscillation output signal having a frequency f which is the sum of the frequency r of the second oscillation signal and the frequency f2 of the second oscillation signal.

[Effect]

1st. The second tunable oscillation elements 12 and 13 generate oscillation signals in which the absolute value of the difference between the oscillation frequency at a specific temperature and the oscillation frequency at an arbitrary temperature is equal and the sign of the difference is opposite. The mixer 17 mixes the first oscillation signal output from the first tunable oscillation element 12 and the second oscillation signal.
is mixed with the second oscillation signal output from the tunable oscillation element 13 to produce an oscillation output signal with a frequency f, which is the sum of the frequency f of the first oscillation signal and the frequency f of the second oscillation signal. create.

〔Example〕

FIG. 1 shows the components of a tunable oscillator according to an embodiment of the present invention. In addition, FIG.
The connection relationship between the tunable oscillator, the second tunable oscillator, and the mixer is shown, and FIG. 3 shows an electrical equivalent circuit of the tunable oscillator of this embodiment.

In FIG. 1, numerals 1 to 11 correspond to the components shown in FIGS. 5 and 6. In Figures 1 to 3, 12.13 represents an oscillation signal in which the absolute value of the difference between the oscillation frequency at a specific temperature and the oscillation frequency at an arbitrary temperature is equal and the sign of the difference is opposite. The first thing that occurs. This is a second tunable oscillation element. 1st. Second
The tuned oscillation elements 12 and 13 are mainly composed of a ferrimagnetic thin film resonator 6, an active element 8, and a matching circuit 10.

The ferrimagnetic thin film resonator 6 is represented as a circuit connected in parallel with a resistor, a coil, and a capacitor. 17 is the first
The first oscillation signal output from the tunable oscillation element 12 and the second oscillation signal output from the second tunable oscillation element 13 are mixed to obtain the frequency f of the first oscillation signal and the second oscillation signal. This is a mixer that creates an oscillation output signal with a frequency f that is the sum of the oscillation signal frequency f2 and the oscillation signal frequency f2. This mixer 17 mainly consists of a slot line 14, a diode 15, and a microstrip line 1.
6 and transformers 21 and 22.

18 is the RF terminal of mixer 17, 19 is the LO of mixer 17
This is the IF terminal of the 20 mixer 17.

The transformers 21 and 22 are equivalent representations of the coupling portion between the slot line 14 and the microstrip line 16. The output terminal of the first tunable oscillation element 12 is the RF terminal 1
8, and the output terminal of the second tunable oscillation element 13 is connected to the LO terminal 19. The IF terminal 20 of the mixer 17 serves as the output terminal of the tuned vibrator according to this embodiment.

In the case of this embodiment, the shape of the ferrimagnetic thin film resonator 6 is such that magnetostatic forward volume waves, magnetostatic backward volume waves, and magnetostatic surface waves are reflected at the edges of the ferrimagnetic thin film and resonance is likely to occur. It is rectangular.

Next, the operation of this embodiment will be explained. The operation of the mixer 17 is explained by Stephen A.
Microwave Mixers (Art
ech) louse, Inc.), so it will be omitted here.

In the first tunable oscillation element 12, a magnetic field is applied perpendicularly to the thin film of the ferrimagnetic film resonator 6, and resonance in the magnetostatic forward volume wave mode occurs, as in the conventional case. In the second tunable oscillation element 13, a magnetic field is applied in parallel to the thin film of the ferrimagnetic thin film resonator 6, causing resonance in the magnetostatic backward volume wave mode.

A description of the basic oscillation operations of the individual tunable oscillation elements 12 and 13 will be omitted since it is the same as that of the conventional device.

The oscillation frequency f due to the resonance of the magnetostatic forward volume wave mode of the first tuned oscillation element 12 and the oscillation frequency 12 due to the resonance of the magnetostatic backward volume wave mode of the second tuned oscillation element 13 are expressed by the following equation. It will be done.

(r = r (Hpl + ΔIIp + (T) +) I.

N・(4πM, 1Δ4πM, (T)) )・・・・・・
(3) f2 ==γ ・ + π 8+
π Matadashi, H= Hpz +ΔHpz(T)
+H2, and )(>>4πM2+Δ4πMz(T), equation (4) can be approximately expressed by the following equation.

f z near ()I + (4KM, +Δ4πM2
(T)l/2)...(4') Therefore, the frequency f of the oscillation output signal taken out from the mixer 17 is f
The sum of l and f2 is the following formula % formula % () (5) Here, Hp+, Hl)z is the first. The magnetic field caused by the permanent magnet 3 of the second tunable oscillation element 12.13 at room temperature, Δ
Hp+(T) and ΔHpt(T) are the first. The magnetic field variation, H+, Hz of the permanent magnet 3 at the temperature T of the second tunable oscillation element 12.13 is the first. Second tunable oscillation element 12.
(4) Magnetic field, Δ4πM, (T), Δ4πM z (T) is the temperature T of the ferrimagnetic thin film 6 of the 1st and second tunable oscillation elements 12 and 13. is the amount of change in saturation magnetization at .

In equation (5), ΔHp+(T) depends on temperature.
1Δl1pz(T) N・Δ4πM, (T)+Δ4π
M.

(T)/2.

When permanent magnet 3 is not used, ΔHfl+(T)=ΔII
p z (T) = 0, and N・Δ4πM, (T)
It is sufficient to select two types of ferrimagnetic thin film resonators 6 such that =Δ4πMz(T)/2.Δ4πM(T) is, for example, yttrium iron garnet (Y
IG) It is known that changes can be made by replacing iron ions in a single crystal IA film with gallium ions.

In addition, in order to reduce the power consumed by the coil 2, a specific magnetic field is applied in advance by the permanent magnet 3 as shown in the figure.
When applying only the magnetic field that makes the frequency variable by the coil 2, by selecting the materials and dimensions of the ferrimagnetic thin film and the permanent magnet 3, ΔHp+(T)N・Δ4′πM, (
T) and ΔHPz(T)+Δ4πM! (T)/2 can be made smaller.

For example, 1st. It is assumed that the second tunable oscillation elements 12 and 13 are both constructed using pure YrG single crystal thin film resonators and permanent magnets 3 having the same characteristics. N is approximately 1.4πM
is 1760 Gauss, Δ4πM is approximately -3,65 Gauss/℃
, then ΔHp + +ΔIIpt= 1
．． The magnetic circuit 4 will be designed to have a temperature of 83 degrees per degree Celsius. Let Hpt=Hpt and the temperature coefficient of the magnetic circuit 4 is 10. 02%, Hp+-Hpz=4575 Oersteds, and when no coil current is flowing, the oscillation frequencies r, , and r of the 1° and second tunable oscillation elements 12.13 are 7.9 GHz, respectively, at room temperature. 15.1
GHz, and the frequency of the oscillator output signal is 23 GHz.

Figure 4 shows the 1. This is a configuration diagram when the magnetic circuit 4 of the second tunable oscillation element 12 13 is shared, and the ferrimagnetic thin film resonator 6 of the second tunable oscillation element 13 has a thin film surface parallel to the magnetic field. are arranged so that Further, by making the magnetic circuit 4 common, the entire tunable oscillator can be made smaller.

In this way, as another embodiment as shown in FIG.
．． The magnetic circuit 4 of the second tunable oscillation element 12 and 13 is shared, and in the ferrimagnetic thin film resonator 6 of the first tunable oscillation element 12, a magnetic field is applied perpendicularly to the ferrimagnetic thin film by the magnetic circuit 4. In the ferrimagnetic thin film resonator 6 of the second tuned oscillation element 13, the oscillation frequency can be further stabilized by configuring the magnetic circuit 4 to apply a magnetic field in parallel to the ferrimagnetic thin film.

In addition, although the above embodiment shows a case where a magnetic resonator is used as the tuned oscillation element, the present invention is not limited to this.
'The Status o' by Ada (et al.)
f MaBnetostatic Devices
” (IEE E Trans, on Magne
tics, vol, MAG-17゜k6,
A similar effect can be obtained when using the magnetostatic delay line shown in Noves+ber 1981).

〔Effect of the invention〕

As described above, according to the present invention, the first oscillation signal that generates the oscillation signals in which the absolute value of the difference between the oscillation frequency at a specific temperature and the oscillation frequency at an arbitrary temperature is equal and the sign of the difference is opposite to each other. ．． A second tunable oscillation element, and a mixer for creating an oscillation output signal having a frequency that is the sum of the oscillation frequency of the first tunable oscillation element and the oscillation frequency of the second tunable oscillation element. Therefore, the temperature change component in the oscillation frequency is canceled out, and even if, for example, the amount of temperature change in the saturation magnetization I4πM of the ferrimagnetic thin film resonator and the amount of temperature change in the magnetic field Ho caused by the permanent magnet are significantly different, the oscillation frequency remains constant over a wide temperature range. This has the effect of suppressing temperature changes as much as possible and improving reliability.

[Brief explanation of drawings]

FIG. 1 shows a tuned oscillation according to one embodiment of the present invention. FIG. 4 is a configuration diagram of a tuned vibrator according to another embodiment, and FIGS.
The figure is a configuration diagram of a conventional tuned token vibrator, and FIG. 7 is a Smith diagram for explaining the operation of the conventional tuned token vibrator. 12...First tunable oscillation element, 13...
...Second tunable oscillation element, 17...Mixer.

Claims (1)

[Claims] first and second tunable oscillation elements that respectively generate oscillation signals in which the absolute value of the difference between the oscillation frequency at a specific temperature and the oscillation frequency at an arbitrary temperature is equal and the sign of the difference is opposite; The first oscillation signal output from the first tunable oscillation element and the second oscillation signal output from the second tunable oscillation element are mixed to produce a frequency of the first oscillation signal and a second oscillation signal. A tunable oscillator comprising: a mixer for creating an oscillation output signal having a frequency equal to the frequency of the oscillation signal;