JP2569320B2 - Frequency divider for high frequency signals - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frequency dividing circuit for high-frequency signals,
The present invention relates to an analog divider circuit using a microstrip line, which is suitable for dividing a microwave band high frequency signal such as F (super high frequency).

[Conventional technology]

Conventional frequency dividers for high frequency signals are described, for example, in IEE, Microwave Theory and Techniques Digest, K-5 (1983).
349 to 351 (IEEE, MTT-S DIGEST, K-5 (198
3), PP349-351).

 FIG. 14 shows a circuit diagram of the frequency dividing circuit.

In FIG. 14, 101 is an input signal terminal, 102 is an output signal terminal, 103 is an FET, 104 is an input bandpass filter, 105 is an output bandpass filter, 106 is a feedback circuit, 107 is a coil, and 108 is a capacitor. .

In this frequency divider circuit, 16G input to the input signal terminal 101
Microwave signal H _z, and outputs from the output signal terminal 102 is divided by 2 to 8GH _z.

The input band-pass filter 104 and the output band-pass filter 105 shown in FIG. 14 are each composed of a microstrip line, and the feedback circuit 106 is composed of a lumped constant circuit composed of a coil 107 and a capacitor 108. .

[Problems to be solved by the invention]

The above prior art, as a feedback circuit 106 from the output of an active element FET103 to the input unit, divided frequency (in this case, 8GH _z) series resonance at a frequency corresponding to,
A lumped constant circuit composed of a coil 107 and a capacitor 108 is used. Therefore, a three-dimensional wiring is required for manufacturing the circuit, and it is difficult to set circuit constants of the coil and the capacitor (for example, as a capacitor) Is 1 / 100pF
You need something for your order. ), The circuit configuration was complicated. Furthermore, there was a problem that frequency division of two or more could not be performed.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art, and to make the whole circuit simple and easy to manufacture.
An object of the present invention is to provide a high-frequency signal frequency dividing circuit capable of dividing an even number of two or more such as frequency division or frequency division by six.

[Means for solving the problem]

In order to achieve the above object, according to the present invention, an open-ended micro-electrode having a length of approximately half the wavelength corresponding to the first frequency is provided between an input terminal and a signal input terminal of a transistor. A first band pass filter having a pass band in the first frequency band, which is constituted by a strip line, and a half of the first frequency is provided between an output terminal and a signal output terminal of the transistor. A second frequency band consisting of a microstrip line with one end grounded and having a length approximately one-fourth of the wavelength corresponding to the first frequency, and a half frequency band of the first frequency as a pass band. A band-pass filter having a length substantially equal to a quarter of the wavelength corresponding to half the first frequency between the signal input terminal and the signal output terminal of the transistor; Microstrip with one end grounded Is constituted by the road, one-half of the first frequency
A third band-pass filter having a pass band of the frequency band is arranged to constitute a high-frequency signal frequency dividing circuit.

[Action]

The transistor is an active element having the functions of frequency mixing and amplification required for the frequency division operation.

The second and third bandpass filters are each constituted by a bandpass filter comprising a quarter-wave resonator of a microstrip line, and the other first bandpass filter is constituted by a microstrip line.
It consists of a bandpass filter consisting of a half-wavelength resonator.

Then, the band-pass filter of the first is set so as to resonate at the input signal frequency f _1, the second and third band-pass filter resonates at half the frequency of the input signal frequency It is set as follows. Then, due to its setting, very close to half the frequency of the input signal frequency f _1,
So that oscillation occurs at a frequency f _2.

When an input signal is input from the input terminal to the circuit in such a state, the frequency mixing operation of the transistor causes
frequency signal of f ₁ -f ₂ becomes the difference is generated, where, if the frequency f ₁ -f ₂ of this generated signal to change the frequency f ₁ of the input signal so as approaching the frequency f _2, the oscillation Frequency f ₂
Is pulled to the frequency f ₁ −f ₂ , Is established. That is, the spectrum is f ₁
Are shown divided by two signal spectrum characteristics, the phase noise is improved than that of f _1. Then, through the second band pass filter, the frequency is output from the output terminal. Is obtained.

Further, the frequency divider circuit according to the present invention, instead of the frequency f ₁ of the signal as an input signal and inputs the signal of frequency 2 · f _1, wherein the first band-pass filter with a 1/2-wavelength resonator this Pass the signal. Then, a signal having a half frequency of the input signal is generated in the circuit, and the frequency Is obtained, and the input signal is divided by four.

Further, the first band-pass filter passes the signal of frequency 3 · f ₁ as well, so that a signal corresponding to f _{1 is} generated in the circuit as described above, Is output from the output terminal, and a signal obtained by dividing the frequency by 6 is obtained.

As described above, according to the present invention, not only frequency division by two but also frequency division by an even number can be performed, and a lumped constant circuit (a circuit composed of a coil, a capacitor, or the like) as in the above-described prior art is used. Since it is not used, the circuit configuration is simple and easy to manufacture.

Note that in the above description, a signal having a frequency of f ₁ −f ₂ is generated by the frequency mixing operation of the transistors. In this case, by mixing the two frequencies, the difference frequency
Not only f ₁ −f ₂ but also the sum frequency f ₁ + f ₂ is generated. In this case, how to process the sum frequency f ₁ + f ₂ which is unnecessary will be described below.

Now two signals to have a system considered in general terms, for example, each of the frequencies if there is f _1/2 and f _1, f _1/2 from the system
When the output circuit is considered to be extracted, the output circuit (and the feedback circuit) is designed so that the frequency of f _1/2 can be easily extracted. Also in the present invention, the output and feedback band pass filters (the second band pass filter and the third band pass filter) are designed so that f _1/2 can be easily extracted.

Since the output band-pass filter resonates at a frequency point that is an odd multiple of f _1/2, it resonates even at the sum frequency, and is output from the output circuit. This is the same component as the harmonic of the frequency of f _1/2 . If output is inconvenient, it can be further attenuated by interposing a band-pass filter, etc.
Usually, it is a component generated when passing through a non-linear element such as an amplifier, and it is considered that there is no particular problem even when output from the circuit of the present invention.

Bandpass filter of the feedback becomes to resonate at (third band-pass filter) even f _1/2 odd times the frequency, it is active designed to prone to oscillation at a frequency of f _1/2 It is sufficiently possible to have design items such as optimization of element performance and circuit constants.

In a frequency dividing circuit including a digital frequency dividing circuit, occurrence of a harmonic is taken as a matter of course, and a countermeasure may be necessary or unnecessary. Therefore, the frequency division of the frequency divider circuit can be considered as taking out the lowest frequency component among the generated frequency components and extracting it, and these phenomena on the frequency axis are plotted on the time axis. It will be easier to understand if expanded.

〔Example〕

 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a high frequency signal frequency dividing circuit as one embodiment of the present invention.

In FIG. 1, 1 is an input signal terminal, 2 is an output signal terminal, 3 is a single gate FET, G is a gate, D is a drain, S is a source, 4 is an input bandpass filter, 5 is an output bandpass filter, 6 Is a feedback bandpass filter.

The FET 3 shown in FIG. 1 is an active element having the functions of frequency mixing and amplification necessary for the frequency dividing operation. An output band-pass filter 5 and a feedback band-pass filter 6 are provided on the output section (ie, the drain D) of the FET 3 and the feedback path from the output section to the input section (ie, the gate G). In addition, both of them are constituted by bandpass filters composed of a quarter-wave resonator of a microstrip line. An input section of the FET 3 is provided with an input band-pass filter 4 and is constituted by a band-pass filter including a half-wave resonator of a microstrip line. A specific example of each bandpass filter will be described later.

Therefore, next, the input band-pass filter 4 is set so as to resonate at the input signal frequency f ₁ , and the output band-pass filter 5 and the feedback band-pass filter 6 are each set to a frequency half of the input signal frequency f _1. Set to resonate with. Then, thereby fairly close to half the frequency of the input signal frequency f _1, oscillation occurs at the frequency f _2.

When an input signal (frequency f ₁ ) is input from the input signal terminal 1 to the circuit in such a state, the input band-pass filter 4 passes a band including the input signal frequency f _1. reached FET 3, and, by frequency mixing operation by non-linearity of the FET 3, the signal of the frequency of f ₁ -f ₂ becomes the difference is generated. Here, the frequency mixing operation is an operation due to the non-linearity of the element. Generally, the FET is superior in the square characteristic to the non-linearity compared to the bipolar transistor.
Therefore, it is said that the frequency mixing operation for generating the sum and difference of the frequencies can be effectively performed.

Therefore, the frequency f ₁ -f ₂ of the generated signal is, as closer to the oscillation frequency f ₂ of the above, when changing the input signal frequency f _1, when fairly close, pull phenomenon by non-linear distortion of the FET3 (When an external signal near this oscillation frequency is input to a self-excited oscillation system such as an oscillation circuit, the self-excited oscillation system synchronizes with the phase of the externally applied signal and oscillates at that signal frequency. refers, for example Masamichi Shimura "non-linear circuit theory" electronic circuit course Vol. 3, 1971 may 20, Shokodo issue, by reference PP63~77), the oscillation frequency f ₂ is the frequency f ₁
−f _{2 so} that Is established.

Then, after that, the output band-pass filter 5 Pass through the band including Only the signal is extracted from the output signal terminal 2 via the output band-pass filter 5.

Next, a case where a signal having a frequency of 2 · f ₁ is input as an input signal to be input to the input signal terminal 1 of the frequency dividing circuit shown in FIG. ₁ instead of the signal having the input signal frequency f _1. explain.

When a signal having a frequency of 2 · f1 is input to the input signal terminal of the frequency divider circuit shown in FIG. ₁ , the input bandpass filter 4 has a microstrip line half-wavelength resonator, and passes this signal.

Because the half-wave resonator of the microstrip line also has a resonance point at a frequency that is an integral multiple of the resonance frequency (in this case, a value equal to the input signal frequency f ₁ ),
This is because the bandpass filter including the half-wavelength resonator has a pass band at a frequency that is an integral multiple of the resonance frequency.
The other output band-pass filter 5 and feedback band-pass filter 6 are different from those of the input band-pass filter 4 because they each comprise a microstrip line quarter-wave resonator. That is, the quarter-wave resonator of the microstrip line has a resonance frequency (in this case,
Since the resonance point is located at a frequency that is an odd multiple of the frequency f ₁ ), the band-pass filter composed of the quarter-wave resonator has an odd multiple of the resonance frequency as a pass band. Eggplant

In the above manner, the signal of the frequency 2 · f ₁ passing through an input bandpass filter 4 reaches the FET3, the frequency mixing operation FET3 described above, the signal of half the frequency of the input signal is produced (i.e. by frequency mixing of a frequency 2 · f ₁ and the oscillation frequency f _2,. the frequency f ₁ is generated), further by frequency mixing of a signal of the frequency f ₁ and the oscillation frequency f _2, similar to the above-mentioned f A signal having a frequency of ₁ −f ₂ is generated. Therefore, the following is similar to the above, Is obtained, and the input signal is divided by four.

It should be noted that, as a precautionary note, since a signal having a frequency close to a half of the input signal frequency, which is the oscillation frequency, and an input signal are input to the non-linear element FET3, the signal is simply 2 Not only the sum or difference of the signals has come out, but also the sum or difference of the sums or differences has come out. Therefore, (3/2) · f ₁ is also generated, and f ₁ is also generated. However, the method of processing unnecessary frequency components among these various generated frequencies is as described above.

In addition to this, same applies if you enter a signal of a frequency 3 · f ₁ as an input signal, the input band-pass filter 4
Since for passing signals in the frequency 3 · f _1, in the same manner as described above in the circuit, created frequency f ₁ corresponding signal is the signal of the frequency difference f ₁ -f ₂ is generated, as a result,
frequency Is output, and a signal obtained by dividing the frequency by 6 is obtained.

As described above, the input band-pass filter 4 allows only a signal having a frequency that is an integral multiple of the input frequency f ₁ to pass therethrough. Is applied to the input signal terminal 1 side. The output band-pass filter 5 and the feedback band-pass filter 6 Only an odd multiple of the frequency of the signal has passed through, the frequency f ₁
Since the signal having a frequency that is an integral multiple of the frequency falls within the stop band, it is not output to the output terminal 2 side.

By the way, the FET 3 in FIG. 1 is as shown in FIG. 2 in an actual circuit.

FIG. 2 is a circuit diagram showing an actual circuit of the FET in FIG.

In the figure, 10 is an input signal terminal, 11 is an output signal terminal,
12 is a FET, G is a gate, D is a drain, S is a source, 13 is a microstrip line, 14 is a microstrip line for bias supply, and 15 is a bias terminal.

The source S of the FET 12 shown in FIG. 2 is directly grounded to obtain a DC and high frequency ground. The microstrip line 13 provided between the gate G and the ground provides a matching condition for the FET 12 so as not to load the input signal and the oscillation signal. FET12 has a bias terminal 1
The power supply voltage obtained from 5 is driven by being applied to a drain D via a low-pass filter type bias circuit based on a quarter-wave resonator, that is, a bias supply microstrip line 14.

Next, FIG. 3 is an explanatory diagram showing a specific example of the input bandpass filter in FIG.

That is, FIG. 3 shows a pattern of a band-pass filter of a single tuning type using a half-wavelength resonator, 19 is an input line, 20 is an output line, 21 is a half-wavelength resonator, 22,23 are voids.

The signal input from the input line 19 transmits the energy to the half-wave resonator 21 through the gap 22 by capacitive coupling, and is transmitted to the output line 20 through the capacitive coupling of the gap 23, The resonator 21 provides a single-tuned bandpass characteristic.

As described above, in the 1/2-wavelength resonator, shows the bandpass characteristics in almost integral multiple of the frequency of the resonance frequency, therefore, the band-pass filter to the input signal f ₁ 2
It has the ability to transmit signals with little loss to f ₁ , 3 · f _1, etc. That is, by forming the input band-pass filter 4 in the band-pass filter, the signal of f _1/2 divided by two with respect to the signal input f ₁ is 4 minutes for 2 · f ₁ of the signal input peripheral the f _1/2 of the signal, the signal of 6 divided by the f _1/2 will be obtained respectively at the signal input 3 · f _1.
Note that frequency division of 6 or more is also possible.

Also, as mentioned above, As a result, the oscillation operation is efficiently performed for the signal of ( ₁₎ , so that a signal of an integral multiple of f1 is efficiently divided and output.

Next, FIG. 4 is an explanatory diagram showing a specific example of the output bandpass filter and the feedback bandpass filter in FIG.

That is, FIG. 4 shows a pattern of a single-tuned band-pass filter using a quarter-wave resonator, 24 is an input line, 25 is an output line, 26 is a quarter-wave resonator, 27 and 28 are voids, respectively. In the case of a half-wavelength resonator, one end is not grounded, but in the case of a quarter-wavelength resonator, one end is grounded.

The operation of this band-pass filter is the same as that of the filter shown in FIG. 3, but as described above, the quarter-wave resonator exhibits band-pass characteristics at an odd multiple of the resonance frequency. The filter is Signals, and It has the ability to transmit with less loss for signals that are an odd multiple of.

That is, in the band-pass filter, by configuring the output band-pass filter 5 and the feedback band pass filter 6 becomes a stopband for an integer multiple of the signal f _1, the input signal f ₁ (or, 2 · f ₁ , 3 · f ₁ , ...) are effectively input to the FET.

Next, FIG. 5 is an explanatory diagram showing another specific example of each bandpass filter in FIG.

That is, FIG. 5 shows a pattern of a double-tuned band-pass filter, in which 41 is an input line, 42 is an output line, 43, 4
4 is a resonator, and 45, 46 and 47 are gaps.

When this bandpass filter is used as the input bandpass filter 4 of FIG. 1, the resonators 43 and 44 are selected to have a half wavelength (one end of the resonator is not grounded), and the output bandpass filter 5 is selected. When used as the feedback band-pass filter 6, the resonators 43 and 44 are selected to / 4 wavelength (one end of the resonator is grounded) and used.

This band-pass filter transmits a signal from the input line 41 to the resonator 43 through the air gap 45 by capacitive coupling.
The light is transmitted to a resonator 44 that is inductively coupled to 43, and transmitted to an output line 42 via a gap 46. Further, since a part of the signal of the input line 41 is transmitted to the output line 42 by the air gap 47 by capacitive coupling,
Attenuation poles are formed at frequency points above and below the double-tuned passband. Even when this bandpass filter is used, the same effect as in the case of the single tuning type can be obtained.

FIG. 6 is a cross-sectional view showing a cross-sectional structure of a bandpass filter using a microstrip line in which a ground conductor is arranged on the back surface of a dielectric substrate on which a microstrip line is formed. Is an input line, 32 is a resonator, and 33 is an output line.

FIG. 7 is a cross-sectional view showing a cross-sectional structure of a band-pass filter composed of a suspended microstrip line having no ground conductor on the back surface, where 34 is a dielectric, 35 and 36 are ground conductors, and 37 is ground. A dielectric part without a conductor, 38 is an input line, 39 is a resonator, and 40 is an output line. In FIG.
The portion having no ground conductor on the back surface (the dielectric portion 37) corresponds to the portion where the resonator 39 is disposed on the front surface (including the peripheral portion of the resonator).

Each of the band-pass filters shown as specific examples in FIGS. 3 to 5 can be constituted by a microstrip line having a form as shown in FIG. 6 or FIG. If the improvement is desired, the suspended line type shown in FIG. 7 is more effective than the embodiment shown in FIG. 6 because a higher unloaded Q can be obtained. It needs to be done enough.

Next, FIG. 8 is an explanatory diagram showing a specific example of a microstrip line pattern for constituting the frequency dividing circuit of FIG.

That is, in FIG. 8, a single-tuned band-pass filter using the half-wave resonator shown in FIG. 3 as the input band-pass filter 5 (hereinafter, referred to as a single-tuned half-wave band-pass filter). ), And a single-tuned band-pass filter (hereinafter, referred to as “band-pass filter”) using the quarter-wave resonator shown in FIG. 4 as the output band-pass filter 5 and the feedback band-pass filter 6.
This is called a single-tuned quarter-wave bandpass filter. ), Each of the single-tuned band-pass filters is composed of the suspended microstrip line shown in FIG.
With G _{a A s} MES FET as FET 3, about 13C as the frequency f ₁
Shows the case of the frequency divider circuit to the signal input of the H _z.

In FIG. 8, (a) shows the pattern surface of the microstrip line, (b) shows the ground conductor surface on the back surface thereof, and the pattern surface and the back surface are α, α ′, β, β ′ correspond to each other.

8, reference numeral 48 denotes a signal input line (corresponding to the portion of the input signal terminal 1 in FIG. 1), and reference numeral 49 denotes a frequency-divided signal output line (first signal line).
The reference numeral 50 corresponds to the mounting pattern of the single gate FET (corresponding to the portion of the FET 12 in FIG. 2).
1 is a microstrip line arranged between the gate G and the ground (corresponding to the microstrip line 13 in FIG. 2), 5
2 is a single-tuned 1/2 wavelength band-pass filter (corresponding to the input band-pass filter 4 in FIG. 1) disposed at the gate G of the input section, and 53 is a single-tuned disposed at the return path from the gate G to the drain D 1/4 wavelength band pass filter (corresponding to the feedback band pass filter 6 in FIG. 1), 54 is a drain D of the output section
Tuned quarter-wave bandpass filter (No. 1)
Reference numeral 55 denotes a microstrip line based on a quarter wavelength line for supplying a bias voltage to the drain D (corresponding to the bias supply microstrip line 14 in FIG. 2). , 56 and 57 are ground conductors, 58 is a back ground conductor, and 59, 60 and 61 are conductor removal parts for making the bandpass filter a suspended microstrip line.

Min divider circuit by a microstrip line pattern shown in FIG. 8, the signal divided by two by the input about 13GH _z (= f ₁₎ and output.

Now, FIG. 9 shows the frequency dividing characteristics of the frequency dividing circuit based on the microstrip line pattern shown in FIG.

That is, FIG. 9 shows the measurement results obtained by taking the frequency of the input signal on the horizontal axis and the output level of the signal divided by 2 on the vertical axis, and confirming the frequency-divided operation by the output level.

In the drawing, there are two measuring line showing the measurement results, which 13.7G the frequency of the input signal (i.e., f ₁₎ from 12.9GH _z
A case of changing to H _z, are those viewed difference pull when changing back from the 13.7GH _z to 12.9GH _z, both are both showed nearly comparable properties. Incidentally, it was measured under the conditions of the input level + 8 dB _m of the input signal.

Next, FIG. 10 is an explanatory diagram showing another specific example of a microstrip line pattern for constituting the frequency dividing circuit of FIG.

That is, in this Figure 10 shows the case of a frequency dividing circuit to set the frequency f ₁ in 6GH _z, (a) shows the pattern surface of the microstrip line, (b) a ground conductor face of the back surface Each is shown. It should be noted that α and α ′ correspond to each other and β and β ′ correspond to the pattern surface and its back surface, respectively.

In Figure 10, 62 denotes a signal input line, 63 divided signal output line, single gate FET (here is 64, G _{a A s} MES F
Use ET. ), 65 is a microstrip line disposed between the gate G and the ground, 66 is a single-tuned half-wave bandpass filter disposed on the input gate G, 67 is from the gate G to the drain D A single-tuned quarter-wave band-pass filter disposed in the feedback path of the above, 68 is a single-tuned quarter-wave band-pass filter disposed in the drain D of the output section,
69 is a microstrip line based on a quarter-wavelength microstrip line for supplying a bias voltage to the drain D, 70 and 71 are ground conductors, 72 is a back ground conductor, 73, 74, 75
Denotes a ground conductor-eliminated portion for forming a band-pass filter with a suspended microstrip line.

The divider circuit according microstrip line pattern shown in FIG. 10, the input signal is, when a signal of about 6GH _z (= f ₁₎ outputs divided by two, about 12GH _z (= 2
・ If the signal is f ₁ ), it is divided by 4 and output, approx.
_If the signal is _z (= 3 · f ₁ ), the signal is divided by 6 and output.

Now, the frequency dividing characteristics of the frequency dividing circuit based on the microstrip line pattern shown in FIG. 10 are shown in FIGS.
Shown in the figure.

In these figures, the horizontal axis represents the frequency of the input signal, and the vertical axis represents the output level of the divided signal. The measuring method is the same as in the case of FIG.

Figure 11 shows the results of the divide-by-two input signals 6GH _z, FIG. 12 shows the result of peripheral quarters input signals 12GH _z, Fig. 13 a signal 18GH _z 6 The result of frequency division is shown. The characteristics indicated by A (thick line) in FIGS. 12 and 13 are characteristics when the frequency of the input signal is increased,
Further, the characteristics indicated by B (thin line) are the characteristics when the characteristics are lowered. In this way, it was confirmed by experiments that the frequency division by 2, 4 and 6 can be performed by one frequency dividing circuit.

〔The invention's effect〕

According to the present invention, all band-pass filters are constituted by microstrip lines, and a lumped constant circuit (a circuit composed of a coil, a capacitor, and the like) used in the related art is not used at all. It is simple and easy to manufacture, and it is possible to not only divide the frequency of the microwave band signal by two, but also to divide the signal even more.
Therefore, PLL control of the VCO and the like can be easily performed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a circuit diagram showing an actual circuit of the FET in FIG.
FIG. 4 is an explanatory diagram showing a specific example of the input bandpass filter in FIG. 1, FIG. 4 is an explanatory diagram showing a specific example of the output bandpass filter and the feedback bandpass filter in FIG. 1, and FIG. FIG. 1 is an explanatory view showing another specific example of each band-pass filter in FIG. 1, FIGS. 6 and 7 are cross-sectional views each showing a cross-sectional structure of a band-pass filter constituted by a microstrip line, and FIG. FIG. 9 is an explanatory view showing a specific example of a microstrip line pattern for forming the frequency dividing circuit of FIG. 1, FIG. 9 is a graph showing the frequency dividing characteristics of the frequency dividing circuit based on the microstrip line pattern of FIG. FIG. 11 is an explanatory view showing another specific example of a microstrip line pattern for constituting the frequency dividing circuit of FIG. 1. FIGS. 11 to 13 are each a diagram of the microstrip line pattern of FIG. Graph showing the frequency division characteristics of that frequency divider, FIG. 14 is a circuit diagram showing a frequency dividing circuit for a conventional high-frequency signals, it is. Description of reference numerals 1 ... input signal terminal, 2 ... output signal terminal, 3 ... FE
T, 4 ... input band pass filter, 5 ... output band pass filter, 6 ... feedback band pass filter, 21 ...
1/2 wavelength resonator, 22, 23 ... air gap, 26 ... 1/4 wavelength resonator, 27, 28 ... air gap, 43, 44 ... resonator, 45, 46, 47 ... air gap, 52, 66 ... Single-tuned 1/2 wavelength bandpass filter, 5
3,54,67,68 …… Single-tuned quarter-wave bandpass filter

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-56-51109 (JP, A) JP-A-57-155807 (JP, A) JP-A-53-129512 (JP, A) 15957 (JP, A) JP-A-55-26752 (JP, A) JP-B-59-37903 (JP, B2)

Claims (3)

(57) [Claims] 1. An open-ended microstrip line having a length of approximately one-half wavelength of a wavelength corresponding to a first frequency is provided between an input terminal and a signal input terminal of a transistor. A first band-pass filter having a frequency band of 1 as a pass band, between the output terminal and the signal output terminal of the transistor,
It is constituted by a microstrip line having a length of approximately a quarter wavelength of a wavelength corresponding to a half frequency of the first frequency and having one end grounded, and a half of the first frequency. A second band-pass filter having a pass band in a frequency band, between the signal input terminal and the signal output terminal of the transistor, approximately four wavelengths corresponding to a half of the first frequency; A third bandpass filter having a length of one-half wavelength and constituted by a microstrip line having one end grounded and having a pass band of a half frequency band of the first frequency is provided. If the signal input from the input terminal is a signal in the first frequency band, the signal is reduced to a half of the first frequency.
If the signal has a frequency band that is an integral multiple of the first frequency band, the signal is divided by (an integer × 2) and output from the output terminal. Frequency divider for high-frequency signals. 2. The frequency divider according to claim 1, wherein each of said first, second and third band-pass filters has a ground conductor on a back surface thereof. A frequency divider for a high-frequency signal, comprising a line resonator. 3. The high frequency signal frequency dividing circuit according to claim 1, wherein said transistor comprises an FET whose source is directly grounded and whose gate is grounded via a microstrip line, wherein the gate of said FET is gated. Is a signal input terminal, and a drain is the signal output terminal.