JPH0347774B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a pulse generation circuit using a step recovery diode.

[Conventional technology]

Conventionally, a balanced pulse generation circuit using a step recovery diode is constructed as shown in FIG. In FIG. 1, T1 is a transformer that converts an unbalanced reference wave input into a balanced one, and X1 is a step recovery diode. Usually, a reference wave input frequency of several + MHz to several hundred MHz is used to extract harmonic pulses in the microwave band.

[Problem to be Solved by the Invention] Generally, pulse generation is determined by the characteristics of the input circuit and the step recovery diode, but in the circuit shown in Figure 1, the pulse generated by the step recovery diode X1 is connected to the reference wave input circuit side. It also spreads to
Loss of generated pulses and resonance in frequency characteristics occurred due to the transformer T1 and the line from the transformer T1 to the step recovery diode X1. The loss is mainly caused by the transformer T1, and the resonance is determined by the transformer T1, the line from the transformer T1 to the step recovery diode X1, and the reverse capacitance Cd of the step recovery diode X1. It was difficult to bring the resonance point of direct reception outside the desired band. Therefore, for the above two reasons, the peak value of the output pulse is lower than the pulse originally generated by the step recovery diode It had become an undesirable characteristic.

It is an object of the present invention to improve the drawbacks of the conventional circuit described above, to eliminate the pulse generated by the step recovery diode, to drive out the resonance in the frequency characteristic out of the desired pulse frequency band, and to achieve the desired pulse frequency. An object of the present invention is to provide a pulse generation circuit that can generate pulse output without causing resonance inside the circuit.

[Means to solve the problem]

According to the present invention, a step recovery diode is provided, and a capacitor is connected in parallel with the step recovery diode via a line having an electrical length l, a reference input signal is applied to both ends of the capacitor, and a reference input signal is applied to both ends of the capacitor.
In a pulse generation circuit that generates a pulse wave containing a harmonic of the reference input signal from both ends of the step recovery diode, a micro-wavelength pulse generator that couples the resonance point determined by the step recovery diode and the electrical length l of the line with the pulse wave. A pulse generating circuit is obtained which is characterized in that it is provided outside the desired frequency band of the wave.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 2 shows the circuit configuration of the present invention. In FIG. 2, T1 and X1 are the same transformer and step recovery diode as in the conventional circuit of FIG.
C1 is a capacitor, and l is an electrical length. The pulse generated by step recovery diode X1 partially propagates to the reference wave input side, but capacitor C1
It is completely reflected due to the shot effect caused by the rays and does not propagate to the transformer T1. Therefore, the loss of generated pulses is improved. According to the inventor's measurements, the second
The peak value of the pulse output from the circuit of the present invention shown in the figure was approximately 1.5 times the peak value of the pulse output from the conventional circuit shown in FIG.

On the other hand, resonance due to the input circuit is caused by capacitor C1
Due to the existence of capacitor C1 shown in FIG.
There is a series resonance of the equivalent circuit having the electrical length l and the reverse capacitance Cd of the step recovery diode X1, and the influence of the input circuit before the capacitor C1 (the transformer T1 and the line from the transformer T1 to the capacitor C1) can be ignored.

The resonance point is expressed as 1/2πN·(2).
Here, L is an inductance determined by the electrical length l. Therefore, for example, the desired frequency (Hz)
＞1/2πN・(2) Electrical length l
By selecting , it is possible to prevent the resonance point from falling within the desired band.

FIG. 4 shows a phase comparator circuit using the pulse generating circuit of the present invention shown in FIG. This circuit samples the microwave input from the terminal 6 using harmonics generated by the step recovery diode X1, and obtains a beat wave output corresponding to the phase difference between the reference wave and the microwave.

FIG. 5 shows the circuit of the present invention (second
The reference wave input is +18 dBm at 100 MHz, and the microwave input level is 0 dBm. The beat wave output voltage data is shown below. As is clear from FIG. 5, when a conventional circuit is used as a pulse generating circuit, the beat wave output voltage is low due to the above-mentioned drawbacks, and resonance occurs due to the frequency characteristics. It can be seen that these points have been significantly improved through use.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, a pulse output can be generated without losing the pulse generated by the step recovery diode and without causing resonance within a desired band. There is.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing the configuration of a conventional pulse generating circuit, FIG. 2 is a circuit diagram showing the configuration of a pulse generating circuit according to the present invention, FIG. 3 is an equivalent circuit diagram of the circuit in FIG. Figure 4 is a circuit diagram showing the configuration of a phase comparison circuit using the pulse generation circuit of the present invention shown in Figure 2, and Figure 5 is a circuit diagram showing the configuration of the phase comparison circuit and pulse generation circuit using the invention shown in Figure 4. 2 is a graph showing an example of beat output characteristics in a phase comparator circuit using the conventional circuit shown in FIG. 1; T1...Transformer, X1...Step recovery diode, C1...Capacitor, l...Electrical length, Cd...
Reverse capacitance of X1, X2, X2...detection diodes.

Claims (1)

[Claims] 1. A step recovery diode and a capacitor connected in parallel with the step recovery diode via a line having an electrical length l, a reference input signal is applied to both ends of the capacitor, and the step recovery diode is in a pulse generating circuit that generates a pulse wave containing harmonics of the reference input signal from both ends of the reference input signal, the desired frequency of the microwave is coupled to the pulse wave at a resonance point determined by the step recovery diode and the electrical length l of the line. A pulse generation circuit characterized in that it is provided outside the band.