JPS6145606A - Doppler signal generator - Google Patents

Abstract

PURPOSE:To spread a frequency deviation and to attain high frequency band by mixing respectively a high frequency signal distributed with a phase difference of 90 deg. by a distributer and a signal from a modulation signal generator and combining them. CONSTITUTION:The high frequency signals Asinomega1t and Asin(omega1t-90 deg.) distributed with a phase difference of 90 deg. by the distributer 21 are inputted respectively to mixers 23, 24. On the other hand, modulation signals Bsinomega2t and Bsin(omega2t- 90 deg.) from a modulation signal generator 22 are inputted to mixers 23, 24, where they are mixed with the high frequency signals. Then the signals of the mixers 23, 24 are combined by a combiner 25 so as to obtain a Doppler signal of ABcos (omega1-omega2) in which the frequency of the inputted high frequency signals is deviated toward lower frequency by the frequency component of the modulation signals.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] When a source of a constant frequency and an object that attempts to capture this frequency move relative to each other, the captured frequency differs from the frequency of the source. . In other words, when they approach each other and intersect, the captured frequency becomes higher,
When they are separated from each other, the frequency becomes lower &
The present invention relates to a Doppler signal generating device that is related to the Doppler phenomenon, and in particular, this invention relates to a Doppler signal generating device that has a high frequency band and a wide frequency deviation width. .

[Prior art]

FIG. 4 shows a conventional Doppler signal generator of this type. In the figure, (1) is a diode phase shifter, (2)
is a control device that controls this diode phase shifter (1),
When the diode phase shifter (1) is driven by this control device (2), as shown in Fig. 5 (N and (B)), the phase of the input high-frequency signal is step-like, and the slope is positive and negative. This figure 5 (2) and (B
), the phase of the high-frequency signal is Q [rad]
to 2 t (rad), or 2 t[yad]
'f (Sec
) time, the input high-frequency signal is As1n(
ω. t+φ), the output of the diode phase shifter (1) is As1n ((11°t+φ+, -1)Aa
in (ayt+φ-2f,j). As a result, the frequency of the human-powered high-frequency signal (=false) is +〒, or f. --It can be seen that IfrI/c shifts.

However, as mentioned above, the diode phase shifter (1)
In the conventional Doppler signal generator using a 2-channel diode phase shifter, it is not only impossible to widen the frequency deviation width due to the response speed of the diode phase shifter itself, but also the input high-frequency signal band cannot be widened, and it is expensive. There are many shortcomings such as:

[Summary of the invention]

The present invention was made with attention to this point, and provides a high-band Doppler signal generator with a wide frequency deviation width by combining a mixer, a signal splitter, a combiner, and a modulation signal generator. There's something I'm trying to do.

[Embodiments of the invention]

1 to 6 each show an embodiment of the present invention. FIG. 1 is a block diagram of a Doppler signal generator, FIG. 2 is a block diagram of a modulated signal generator, and FIG. 3 is a block diagram of a modulated signal generator. The phase relationship diagram of the signals is shown. First, in Figure 1, (b) is a distributor that distributes high-frequency signals with a phase difference of 90 degrees, and (a)
is a modulation signal generator, Kan.

(c) is a pair of mixers that mixes the high frequency signal distributed by the above-mentioned distributor (company) and the modulation signal from the above-mentioned modulation signal generator (a); A synthesizer that combines the outputs of Ruru.

Now, the manually generated high frequency signal is distributed by the distributor (c), and the high frequency signal input to one mixer is As1.
Let nω be 1, and let the high frequency signal input to the other mixer be As1n (ωIL 9δ). Also,
The modulation signal input to the 10,000 mixer kan by the modulation signal from the modulation signal generator (b) is Bs1nω2t, and the modulation signal input to the other mixer (c) is Bs1n(a
lIt-90), the output of one mixer (2) is 2 AB (co' (ωI -ω!) t-co
8-(s, +ω2)t), and the output of the other mixer (c) is T AB (cos (st+ %) t+
aos (ax+ω,)t). Next, these two signals are combined by a combiner (c) to obtain a Doppler signal of AB cos (ω1-ω1)1. This shows that the frequency of the input high-frequency signal has shifted lower by the frequency of the modulation signal. In addition, the above mixer (goods), (
It goes without saying that by reversing the phase of the manually inputted modulation signal in c), it is possible to shift it higher by the frequency of the modulation signal.

Next, in the modulation signal generation device shown in FIG. 2, 01 is a first storage device that stores a value obtained by digitizing a sine wave, and 0 is a second storage device that stores a value obtained by digitizing a cosine wave. , elI is a first counter that reads the value stored in the first storage device o1vc, (b) is a second counter that reads the value stored in the second storage device (b), (to) is a first digital-to-analog converter that converts the output from the first storage device 0 to a sine wave, and (2) is a first digital-to-analog converter that converts the output from the second storage device (b) to a sine wave.
a second digital-to-analog converter for converting the a-wave into a wave; (b) a first amplifier for amplifying the output from the first digital-to-analog converter (2); (to) the second digital to analog converter; A second amplifier amplifies the output from the analog converter (c).

Now, both the storage devices C11, (32) store the changes of one cycle of the sine wave and the cosine wave as digitized values, and the counters (to) and (b):
When reading from the same address in both storage devices (o) and (a) to higher addresses in order, as shown in the phase relation diagram of the modulation signal in Fig. output,
In other words, the signal of output [1] is 9 compared to the signal of [2]
If the rf phase becomes a signal that is advanced, and if only one first storage device 01 is read out in order from the same address to a lower address, the signal of output [1] will be delayed by 9o0 compared to the signal of output [2]. It becomes a signal.

Furthermore, the frequencies of the signals of the output [1] and output [2] can be set by the cycle of the clock that operates the first and 20th counters (to), 04, and both storage devices o1
．． If the number of addresses of as is n and the clock period is Tc, then the frequency of conversion signals [1] and [2] is 1/(n
-Tc) [Hzl.

〔Effect of the invention〕

As described above, according to the present invention, by combining a mixer, a signal splitter, a combiner, and a modulation signal generator, a high-bandwidth Doppler signal generator with a wide frequency deviation width can be provided at low cost. There is something that has the effect that it can do.

[Brief explanation of the drawing]

Figures 1 to 6 show an embodiment of the present invention, in which Figure 1 is a block diagram of a Doppler signal generator, Figure 2 is a block diagram of a modulated signal generator, and Figure 3 is a modulated signal generator. FIG. 3 is a phase relationship diagram of signals. FIG. 4 is a block diagram showing a conventional Doppler signal generator,
FIG. 5 shows a phase change diagram of a conventional diode phase shifter. In the figure, (2) is a distributor, (2) is a modulation signal generator, (c) is a mixer, (2) is a combiner, on (to) is a storage device, (to) He;t counter, ( 2) e4tt digital analog converter, (b) o4 is an amplifier output. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Patent Attorney Sanro Kimura Diagram 5 (A) (B) ←--1-1 Tsuyoshi Toki (sec, l = Procedural amendment (voluntary) December 1982 268

Claims (2)

[Claims] (1) A distributor that distributes high-frequency signals with a 90° phase difference, a modulation signal generator, and mixes the high-frequency signal distributed by the distributor and the modulation signal from the modulation signal generator. 1. A Doppler signal generation device comprising a pair of mixers and a combiner that combines the outputs of both mixers. (2) Claim 1, characterized in that the modulation signal generating device is constituted by a pair of storage devices, a pair of counters, a pair of digital-to-analog converters, and a pair of amplifiers. The Doppler signal generator described in Section 1.