JPH0552464B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a radio wave monitoring receiver that receives, monitors and analyzes radio waves randomly generated in the real sky.

<Prior Art> Conventionally, this type of radio wave monitoring receiver sweeps the frequency of a local oscillator of the receiver over the entire receiving frequency range or within a necessary range in order to receive and analyze a wide frequency range. The frequency spectrum of the received signal can be observed using a known spectrum analyzer. Furthermore, in order to analyze any received signal, the above-mentioned swept received signal is displayed on a display, and the received frequency is measured by aligning a marker corresponding to the frequency.

By the way, monitoring the entire band over a wide frequency range,
In order to receive and analyze an arbitrary wave, it is necessary to make the local oscillation frequency completely match the desired receiving frequency. In order to tune the local oscillation frequency to a desired wave from a wide frequency band, it usually requires several stages of coarse tuning and then progressively more precise tuning. In other words, the sweep frequency is swept over the entire band, and then the sweep band is gradually narrowed, and finally the sweep band is narrowed to just enough to obtain the required frequency resolution, and the sweep reception is performed as described above. Align the marker with the signal and receive the desired signal.

For this reason, a frequency synthesizer for sweeping the local oscillator must have a sweep width of several steps in any frequency band, resulting in a complicated circuit configuration and an expensive device.

FIG. 1 is a block diagram of a conventional wideband radio monitoring receiver. To briefly explain this conventional example, a signal received in a wide frequency range by a receiving antenna 1 is amplified to a predetermined value by a high frequency amplifier circuit 2, and then sent to a mixer 3 to be sent to a swept frequency synthesizer 4 for sweeping local oscillation. The difference between the frequency of the received signal and the frequency of the swept local oscillator signal is mixed with the signal.
It appears at the input of the IF amplifier 5 only when it reaches the IF frequency, and is amplified by a predetermined amount by the IF amplifier 5. On the other hand, the bandwidth of the IF amplifier 5 matches the frequency accuracy measured by this monitoring receiver. That is, if
The narrower the bandwidth of the amplifier 5, the more accurate the measurement frequency can be. Moreover, this frequency accuracy and the sweep time of the entire frequency band are inversely proportional, and are expressed by the following equation.

Sweep time for all frequency bands T=KBw/△f ² Here, K is a constant determined by the IF filter, and △f represents frequency resolution.

Therefore, in order to increase measurement frequency accuracy, the sweep time must be slowed down. In order to display and monitor the signals received in this way, either use a display 9 with strong afterglow properties, or store the received signal in a sweep conversion circuit 8 or the like and use a sweep time suitable for the display. It is necessary to read out and display the stored signal data.

Also, since the above marker corresponds to the frequency axis, the frequency accuracy of this marker is directly related to the measurement frequency accuracy, so the IF frequency is usually added to the swept local oscillation signal to generate a frequency marker using a pseudo reception frequency. A frequency marker method is used in which the received frequency is measured by generating the signal in the receiver 6 and applying the signal to the receiver input terminal. As described above, conventional radio wave monitoring receivers require a complex sweep frequency synthesizer 4 for switching the sweep band into several stages, a frequency marker generator 6 for increasing measurement frequency accuracy, and a sweep conversion circuit 8 for display monitoring. Then,
This has the disadvantage that the circuit of the monitoring receiver is complex and expensive.

<Problems to be Solved> An object of the present invention is to provide a radio wave monitoring receiver that receives arbitrary radio waves in a wide frequency band with a simple and inexpensive device configuration.

<Means for solving the problem> The radio wave monitoring and selling device according to the present invention sweeps the frequency of a local oscillator over the entire reception frequency range or in part, using radio waves in the real sky that are randomly generated over a wide frequency range. It is a radio wave monitoring receiver that instantly receives the received signal, measures the radio wave format including the frequency, occupied bandwidth, and modulation type, and displays the results. a plurality of filters that frequency-divide the received signal, and a storage circuit that temporarily stores each of the signals frequency-divided by the filters, and the storage circuit maintains the dividing ability until the presence or absence of the received signal can be identified. Equipped with a memory for full-band monitoring that stores dropped signals and a memory for precision measurement that stores the received signal in the minimum resolution unit for the swept frequency range.
By specifying the readout area of the precision measurement memory, the sweep width can be arbitrarily changed to receive radio waves.

<Example> Next, an example of the present invention will be described based on FIG. 2.

FIG. 2 is a block diagram showing an embodiment of a radio wave monitoring receiver according to the present invention.

In the figure, 1 is a receiving antenna, 2 is a high frequency amplifier, 3 is a mixer, 4 is a frequency synthesizer, and 5 is a
10 is a filter circuit, 11 is a memory circuit, and 9 is a display device.

The received signal induced in the receiving antenna 1 is amplified by a predetermined value by a high frequency width amplifier 2, mixed with a swept local oscillation signal from a swept frequency synthesizer 4 by a next mixer 3, and inputted to an IF amplifier 5. This swept local oscillation signal is swept stepwise in this embodiment, unlike the conventional swept local oscillation signal shown in FIG. 1, which sweeps continuously. This number of steps is determined by a filter circuit 10 connected after the IF amplifier 5. This filter circuit 10 is constructed in parallel so that the center frequency is sequentially shifted by a frequency of required frequency measurement accuracy.

For example, if the number of filters is N and the bandwidth of the filter is _BIF , then the number of steps n of the swept frequency synthesizer is n=Bw/N× _BIF (where Bw represents the entire frequency band). . Therefore, the frequency synthesizer sequentially switches the frequency in n steps.
Can receive all frequency bands.

On the other hand, since the frequency band of the IF amplifier 5 is equal to the sum of the bandwidths of all filters in the filter circuit 10, one step of the frequency synthesizer simultaneously receives reception signals for N filters. This received signal is detected in each channel by the filter circuit 10 and stored in the next storage circuit 11. In this embodiment, if all received signals are stored in the minimum resolution unit, the memory capacity will be enormous, so we have two memories: one for full-band monitoring and one for precision measurement.
The system consists of several types of memory, and the resolution of the full-band monitoring memory is lowered until the presence or absence of a received signal can be identified, so that the memory capacity is not increased. Furthermore, the accuracy measurement memory stores the frequency range of one step in the step sweep described above in the minimum resolution unit.

In addition, the display 9 generally cannot accurately measure the received signal when displaying a wide frequency range with the minimum resolution, so as shown in the explanation of the conventional method, the sweep bandwidth is gradually narrowed until the received signal can be measured precisely. are doing.

Conventionally, the sweep width of a sweep frequency synthesizer is switched, but in this embodiment, the display bandwidth is switched by changing the read range of the precision measurement memory.

That is, the conventional marker corresponds to specifying a memory address in this embodiment, and the sweep width corresponds to specifying a readout area. Therefore, since everything can be processed digitally, the accuracy of the measurement frequency can be achieved with a simple circuit up to the accuracy of one filter bandwidth of the filter circuit 10.

<Effects of the Invention> As explained above, according to the bright radio wave monitoring receiver of the present invention, a stepwise switching synthesizer can be used instead of using a continuous sweep synthesizer, and furthermore, addressing and reading of the memory circuit can be performed. Since areas are switched, highly accurate analysis is possible with a simple circuit configuration, and costs can be reduced.

Moreover, since all the input signals existing in a wide band are recorded in memory and the necessary parts are stored in high-resolution memory, it is possible to precisely analyze any signal at any time.
By storing input data in memory and changing the readout range of this memory, any signal can be observed at any time (even when the signal does not exist in real space) using a display, etc. be.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a conventional radio wave monitoring receiver. FIG. 2 is a block diagram showing the configuration of an embodiment of a radio wave monitoring receiver according to the present invention. 1... Receiving antenna, 2... High frequency amplifier, 3
... Mixer, 4 ... Sweep frequency synthesizer, 5
...IF amplifier, 6...Frequency marker generator, 7
...detection circuit, 8 ... sweep conversion circuit, 9 ... display, 10 ... filter circuit, 11 ... memory circuit.

Claims (1)

[Claims] 1 Radio waves in the real sky that are randomly generated over a wide frequency range are instantly received by sweeping the frequency of a local oscillator over the entire reception frequency range or in part, and the frequency of the received signal is , an occupied bandwidth, a radio wave monitoring receiver that measures a radio wave format including a modulation type, and displays the results, the receiver comprising a plurality of filters for frequency-dividing the received signal, which are configured by sequentially shifting at predetermined frequency intervals. and a storage circuit that temporarily stores each of the signals frequency-divided by the filter, and the storage circuit includes a full-band monitoring memory that stores the signal whose division power has been reduced until it is possible to identify the presence or absence of a received signal. , is equipped with a precision measurement memory that stores the received signal in the minimum resolution unit for the swept frequency range, and can receive radio waves by arbitrarily changing the sweep width by specifying the readout area of the precision measurement memory. Features of radio wave monitoring receiver.