JP2917580B2 - Signal amplitude measurement device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal amplitude measuring device, and more particularly to a signal amplitude measuring device having a measuring function for each frequency unit.

[0002]

2. Description of the Related Art As shown in FIG. 3, a conventional signal amplitude measuring apparatus includes a frequency filter bank 1 for separating an input signal for each frequency, and a detecting circuit 2 for detecting signals separated for each frequency. The signal detection circuit 3 determines whether or not there is an output of each of the detection circuits 3 by comparing with the reference level, and selects the number of the full bank 1 in which the signal is detected from the outputs of the signal detection circuits 3. And a signal selection circuit 4 for outputting the signal, and an amplitude measurement circuit 7 for measuring the amplitude of the input signal based on the detection time signal of the signal output from the signal selection circuit 4.

[0003]

[Problems that the Invention is to Solve In this conventional signal amplitude measurement apparatus, based on the detection time signal of the input signal as it is being amplitude measurement, the signal selection circuit 4
One signal is output and based on the detection time signal.
Even if amplitude measurement is performed, the frequency
If there are multiple signals with different numbers,
That is, the amplitude of a signal on which a plurality of signals are superimposed is measured. An object of the present invention is to provide a signal amplitude measuring device capable of separately measuring the amplitudes of a plurality of signals having different frequencies existing at the same time.

[0004]

According to the present invention, there is provided a signal amplitude measuring apparatus comprising: a signal amplitude measuring apparatus having a frequency filter bank, a detection circuit, a signal detecting circuit, a signal selecting circuit, and an amplitude measuring circuit; A frequency tuning control circuit that generates a frequency tuning signal corresponding to the signal to be output, and a frequency tuning circuit that is tuned to a frequency according to the output of the frequency tuning control circuit and passes only the signal of the tuning frequency among the input signals. The amplitude measurement circuit is configured to measure the amplitude of a signal that has passed through the frequency tuning circuit based on a detection time signal of a signal output from the signal selection circuit. In this case, the frequency tuning circuit includes a local oscillation circuit that generates a signal having a frequency based on the output of the frequency tuning control circuit, a mixer that mixes an input signal with an output signal of the local oscillation circuit and performs frequency conversion, and an output from the mixer. And a band-pass filter for band-pass filtering the signal to be transmitted.

[0005]

According to the present invention, only a signal having a frequency tuned to the signal selected by the signal selection circuit is passed through the frequency tuning circuit, and only the passed signal is subjected to amplitude measurement by the amplitude measurement circuit. It is possible to separate and measure the amplitudes of a plurality of signals having different frequencies existing at the same time.

[0006]

Next, the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a first embodiment of the present invention. In the figure, 1 is a frequency filter bank,
The input signal is separated for each frequency and output. Reference numeral 2 denotes a detection circuit that detects and outputs each output separated by the frequency filter bank 1. Reference numeral 3 denotes a signal detection circuit which determines the presence or absence of an output of the detection circuit 2 and outputs a result. 4
Is a signal selection circuit for selecting and outputting one of the outputs of the signal detection circuit 3. A frequency tuning control circuit 5 generates and outputs a frequency tuning signal from the output of the signal selection circuit 4. Reference numeral 6 denotes a frequency tuning circuit which varies a tuning frequency according to the output of the frequency tuning control circuit 5, and selects and outputs only a frequency corresponding to the frequency tuning signal from the input signals input. Reference numeral 7 denotes an amplitude measurement circuit which measures the amplitude of the output of the frequency tuning circuit 6 based on the signal detection time signal output from the signal selection circuit 4 and outputs the measurement result.

According to this configuration, the signal selection circuit 4 selectively selects one of the detected signals from the frequency tuning control circuit 5.
, And the frequency tuning control circuit 5 sets the tuning frequency of the frequency tuning circuit 6 based on this output. For this reason, the input signal passes through the signal of the frequency tuned by the frequency tuning circuit 6, and only the passed signal is amplitude-measured by the amplitude measurement circuit 7, so that a plurality of signals having different frequencies are input at the same time. Also in this case, the amplitude of the signal separated for each frequency can be measured.

FIG. 2 is a block diagram showing a second embodiment of the present invention. The configuration is such that the frequency tuning circuit 6 in FIG. 1 is replaced by a local oscillation circuit 8, a mixer 9, and a BPF (bandpass filter) 10. That is, the input signal is separated for each frequency by the frequency filter bank 1 and detected and output by the detection circuit 2. The signal detection circuit 3 determines the presence or absence of the output, and outputs the result. The signal selection circuit 4 selects and outputs one of the outputs. The frequency tuning control circuit 5 generates a frequency tuning signal from this output, and controls the local oscillation frequency which is the output of the local oscillation circuit 8.

In the mixer 9, the input signal is frequency-converted by the local oscillation frequency.
The BPF 10 selects a frequency corresponding to the frequency selected by the signal selection circuit 4, and the amplitude measurement circuit 7 measures the amplitude of the signal output from the BPF 10 based on the signal detection time signal output from the signal selection circuit 4, The measurement result is output. Accordingly, since the amplitude of the input signal is measured after passing through the BPF 10, even when a plurality of signals having different frequencies are input at the same time, the amplitude of the signal separated for each frequency can be measured. .

[0010]

As described above, the present invention comprises a frequency tuning circuit for passing only a signal having a frequency tuned to the signal selected by the signal selection circuit, and only the passed signal is used by the amplitude measuring circuit. Since it is configured to measure the amplitude, even if there are multiple signals having different frequencies at the same time in the input signal, it is possible to separate and measure the amplitude of only the signal passed through the frequency tuning circuit from these multiple signals. Has an effect that can be. In the present invention, the frequency
For the filter bank, the frequency in the detection circuit for each frequency
The signal detection circuit determines the presence or absence of wave number output and
Selection from the signal detection to signal selection
Becomes extremely simple.

[Brief description of the drawings]

FIG. 1 is a block diagram of a first embodiment of a signal amplitude measuring device according to the present invention.

FIG. 2 is a block diagram of a second embodiment of the signal amplitude measuring device of the present invention.

FIG. 3 is a block diagram of a conventional signal amplitude measuring device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Filter bank 2 Detection circuit 3 Signal detection circuit 4 Signal selection circuit 5 Frequency tuning control circuit 6 Frequency tuning circuit 7 Amplitude measurement circuit

Claims (2)

(57) [Claims] 1. A frequency filter bank for separating an input signal into a plurality of different frequencies, a detection circuit for detecting each frequency output of the frequency filter bank, and presence / absence of a plurality of frequency outputs from the detection circuit. A signal detection circuit, a signal selection circuit that selects one of the outputs of the signal detection circuit based on the determination by the signal detection circuit, and a signal selection circuit based on a signal output from the signal selection circuit.
A frequency tuning control circuit for generating a frequency tuning signal corresponding to each frequency of the frequency filter bank, and a frequency tuned to a frequency in accordance with an output of the frequency tuning control circuit, and an output of the frequency tuning control circuit among the input signals. A frequency tuning circuit that passes only a signal of a tuning frequency; and an amplitude measurement circuit that measures an amplitude of a signal that has passed through the frequency tuning circuit based on a detection time signal of a signal output from the signal selection circuit. A signal amplitude measuring device characterized by the above-mentioned. Wherein said frequency tuning circuit includes a local oscillator circuit for generating a signal of a frequency based on an output of the frequency tuning control circuit, a mixer which to frequency-conversion mixer the input signal and the output signal of the local oscillator circuit When the signal amplitude measuring apparatus according to claim 1 comprising a signal output from the mixer is constituted by a band-pass filter unit for band-filters.