JPH0478237A - Radio transmitter-receiver - Google Patents

Abstract

PURPOSE:To easily implement the overall test and to easily discriminate a fault location by setting a frequency difference between a transmission intermediate frequency and a reception intermediate frequency equal to a frequency difference between a transmission frequency and a reception frequency. CONSTITUTION:A transmission frequency fT and a reception frequency fR are set while being parted by a difference frequency f1 and a transmission intermediate frequency f1T and a reception intermediate frequency f1R are set similarly while being parted by a difference frequency f1 similarly. In the case of conducting a radio line loopback test, an output signal 2 of a transmitter 1 is branched and inputted to a mixer 71. The mixer 71 receives a signal from an oscillator 70 generating a signal having the difference frequency f1 of the transmission frequency and the reception frequency and converts the output signal 2 into a signal 74 having the reception frequency. A switch 80 receives a reception signal 5 from an antenna or the converted signal 74, selects the converted signal 74 in the case of the loopback test and inputs it to a receiver 4. Thus, the test of the system passing through an intermediate frequency section 102, a high frequency section 101 of the transmitter 1, a high frequency section 104 and an intermediate frequency section 402 of the receiver 4 is conducted.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a wireless transmitting/receiving device, and more particularly to a wireless transmitting/receiving device having a wireless line return test circuit.

(Prior Art) As a radio transmitter/receiver having a radio line return test circuit, for example, the one shown in FIG. 4 is known.

In FIG. 4, the wireless line loopback test circuit includes a loopback oscillator 41 that generates a signal with a difference frequency between the transmitting frequency and the receiving frequency, a part of the output signal 2 from the transmitter 1!11 to the transmitter antenna 3, and an oscillator a mixer 42 that mixes the output signal of the receiver 41 to form a signal at the receiving frequency and outputs the signal, and a switch (SW) 43 that switches between the received signal 5 from the receiving antenna 6 and the output signal of the mixer 42 and outputs the signal to the receiver 4. Consists of.

The original transmission/reception operation is as follows. The transmission ml includes a high frequency section 101 and an intermediate frequency section 102, but the intermediate frequency section 10
The output signal of No. 2 is converted into a high frequency signal, which is a transmission frequency signal, in a high frequency section 101, and is amplified. This is transmitter 1
is radiated from the transmitting antenna 3 as an output signal 2.

On the other hand, in normal transmitting and receiving operation, 5W43 uses the receiving antenna 6.
Therefore, the received signal 5 received by the receiving antenna 6 is sent to the receiver 4 via 5W43
Enter. The receiver 4 has a high frequency section 401 and an intermediate frequency section 4.
02, the received signal 5 is amplified and converted to an intermediate frequency in the high frequency section 401, and inputted to the intermediate frequency section 402, where it is received and processed.

Next, when performing an operation test on the wireless transmitting/receiving device alone, the output of the mixer 42 is selected by switching 5W43. As a result, the output signal 2 of the transmitter 1 is converted by the mixer 42 into a signal having the same frequency as the received signal 5, and is input to the receiver 4. That is, the intermediate frequency section 102 and the high frequency section 1 on the transmitting side
01, the signal passes through the high frequency section 401 and intermediate frequency section 402 on the receiving side in this order, and a comprehensive test of the transmitting system and the receiving system is performed.

(Problem to be Solved by the Invention) In the conventional wireless line return test circuit described above, when a fault occurs, although comprehensive testing can be performed, it is difficult to determine whether the fault is in the high frequency section or the intermediate frequency section. There is a problem that it takes time to determine the location of the failure and to restore it.

In other words, from the standpoint of investigating the cause, it is necessary to not only perform a comprehensive test but also to be able to determine whether the fault is in the high frequency section or the intermediate frequency section, but conventional test circuits do not take this into account. It has not been done. This is partly due to the fact that the configuration of conventional wireless transmitting/receiving devices does not allow for easy loopback tests in intermediate frequency bands.

As is well known, the conversion between a high frequency signal and an intermediate frequency signal is
This is done by mixing the signal of a local oscillator that generates a frequency that is the difference between the two, but when high-speed switching between transmitting and receiving frequencies is required, it is often done to make the output signal of this local oscillator shared between transmitting and receiving. be exposed. In such a case, the intermediate frequency for transmission and reception is set arbitrarily, so
The difference in intermediate frequency between transmission and reception is different from the difference between the transmission frequency and the reception frequency. Therefore, if a folding test is to be performed in the intermediate frequency band, it is necessary to configure a dedicated test circuit separately from the comprehensive test circuit. This results in an increase in the size and cost of the device, and the reality is that there is no skill in incorporating it into the device.

The present invention has been made in view of these problems, and its purpose is to provide a wireless transmitting/receiving device having a wireless line return test circuit that can easily perform not only a comprehensive test but also a fault location determination circuit. be.

(Means for Solving the Problems) In order to achieve the above object, a wireless transmitter/receiver according to the present invention has the following configuration.

That is, the wireless transmitting/receiving device of the first invention includes: a transmitter including a transmitting intermediate frequency section and a transmitting high frequency section; and a receiver including a receiving high frequency section and a receiving intermediate frequency section; setting a difference frequency between a transmission intermediate frequency and a reception intermediate frequency to be equal to a difference frequency between the transmission frequency and the reception frequency; an oscillator generating a signal at the difference frequency;
a first mixer that mixes a part of the output signal from the transmission high frequency section to the transmission antenna and the output signal of the oscillator to form a reception frequency signal; a first switch that switches the received signal and outputs it to the receiving high frequency section; mixes a part of the output signal from the transmitting intermediate frequency section to the transmitting high frequency section with the output signal of the oscillator; a second mixer that forms a signal; a second switch that switches between the output signal of the second mixer and the output signal of the reception high frequency section and outputs it to the reception intermediate frequency section; It is characterized by:

Further, a wireless transmitting/receiving device according to a second aspect of the present invention includes: a transmitter including a transmitting intermediate frequency section and a transmitting high frequency section; and a receiver including a receiving high frequency section and a receiving intermediate frequency section; setting a difference frequency between a transmission intermediate frequency and a reception intermediate frequency to be equal to a difference frequency between the transmission frequency and the reception frequency; an oscillator generating a signal at the difference frequency;
a first switch that switches and outputs a part of the output signal from the transmission high frequency section to the transmission antenna and a part of the output signal from the transmission intermediate frequency section to the transmission high frequency section; an output of the first switch; a mixer that mixes the signal and the output signal of the oscillator to form and output a reception frequency signal and a reception intermediate frequency signal; and a mixer that receives the output signal of the mixer and switches between the reception frequency signal and the reception intermediate frequency signal; a second switch for outputting; a third switch for switching between a reception signal from a reception antenna and a reception frequency signal, which is an output signal of the second switch, and outputting the same to the reception high frequency section; and a fourth switch that switches between the output signal and the reception intermediate frequency signal, which is the output signal of the second switch, and outputs the same to the reception intermediate frequency section.

(Function) Next, the function of the wireless transmitter/receiver of the present invention configured as described above will be explained.

According to the wireless transmitter/receiver of the present invention, since the difference frequency between the transmission intermediate frequency and the reception intermediate frequency is set equal to the difference frequency between the transmission frequency and the reception frequency, the loopback oscillator is shared and the high frequency band is transmitted. It is possible to configure a test circuit that can perform aliasing tests in the intermediate frequency band and aliasing tests in the intermediate frequency band.
Not only a comprehensive test but also a fault location can be easily determined.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a wireless transmitting/receiving device according to an embodiment of the present invention. First, in the wireless transmitting/receiving device of the present invention, a local oscillator (not shown) used for transmitting and receiving is used for both transmitting and receiving, but unlike conventional In the present invention, as shown in FIG. 2, the transmission frequency ft and the reception frequency fR are set apart by a difference frequency ft, and the transmission intermediate frequency flr and the reception intermediate frequency fl
R and are set apart by the same difference frequency f1. Therefore, the local frequency fL is ft f+t=fp+
It is set at the fI* position.

In such a wireless transmitting/receiving device, the folding test circuit according to the first embodiment includes one oscillator 70 and two mixers 71 . It consists of SW 72 and two SWs 60 and 61.

In FIG. 1, when performing a radio line return test, the output signal 2 of the transmitter 1 is branched and input to a (first) mixer 71. In this mixer 71, the output signal 2 is converted into a reception frequency signal 74 by a signal from an oscillator 70 that generates a signal with a frequency difference f1 between transmission and reception. The switch 80 selects either the received signal 5 from the antenna or the converted signal 74, and during the loopback test, the converted signal 74 is selected and input to the receiver 4.

As a result, the intermediate frequency section 102 of the transmitter 1 and the high frequency section 1
01, Reception t! 14 high frequency section April, intermediate frequency section 402
It is possible to test a system that passes through the steps in order. This is a folding test in the same high frequency band as explained in the conventional example.

Next, a case where folding is performed in an intermediate frequency band will be described. In this case, the difference in intermediate frequency between transmission and reception is also f
1, the return oscillator 70 can be shared.

The transmission intermediate frequency signal 103 is converted into a reception intermediate frequency signal 403 by the (second) mixer 72, and similarly selected by the (second) switch 81, and sent to the reception intermediate frequency section 402 of reception 1!14. is input. This allows testing of the system passing through the intermediate frequency section 102 of the transmitter 1 and the intermediate frequency section 402 of the receiver 4.

When a fault occurs, by performing the above two tests, it is possible to determine whether the fault is in the high frequency section or the intermediate frequency section.

Next, FIG. 3 shows a wireless transmitting/receiving device according to another embodiment of the present invention. The folding test circuit according to the second embodiment is as follows:
In the first embodiment, two mixers 71
, one mixer 73 is provided in place of the mixer 72, a switch 82 and a switch 83 are connected to each of the input and output, and the input and output of the mixer 73 is switched.
3 is also shared, further simplifying the configuration. Since the operation is similar to that of the first embodiment, the explanation will be omitted.

(Effects of the Invention) As explained above, according to the wireless transmitting/receiving device of the present invention, the difference frequency between the transmission intermediate frequency and the reception intermediate frequency is set equal to the difference frequency between the transmission frequency and the reception frequency. It is possible to configure a test circuit that can perform loopback tests in high frequency bands and loopback tests in intermediate frequency bands by sharing a loopback oscillator, making it possible to easily identify failure locations as well as comprehensive tests. In addition, since the oscillator for folding is shared, the oscillator space can be reduced in terms of W configuration, which has the effect of making the device more compact.

Furthermore, if it is necessary to synchronize the transmitting and receiving frequencies,
This return oscillator also needs to be synchronized, but in this case as well, since only one oscillator is required, only one synchronization circuit is required, which has the effect of simplifying the configuration.

[Brief explanation of the drawing]

FIG. 1 is a configuration block diagram of a wireless transmitting/receiving device according to an embodiment of the present invention, FIG. 2 is an rIiJgA diagram of transmitting and receiving frequencies, intermediate frequencies for transmitting and receiving, and local frequencies, and FIG. A configuration block diagram of such a wireless transmitting/receiving device,
FIG. 4 is a block diagram of the configuration of a conventional wireless transmitter/receiver. 1... Transmitter, 3... Transmitting antenna, 4... Receiver, 6... Receiving antenna, 70... Oscillator, ? 1,72.73
...Mixer, 80,81.8243...
...Switch, 101,401--...High frequency section, 102,402......Intermediate frequency section. False wire sauce moxibustion of the present invention A Kyogiri 4 Birch 1N cure (■) 19
5 No C) Liao 2L Relief Guide 212 Agent Patent Attorney Yoshihiro Yahata

Claims (2)

[Claims] (1) In a radio transmitting/receiving device consisting of a transmitter including a transmitting intermediate frequency section and a transmitting high frequency section; and a receiver including a receiving high frequency section and a receiving intermediate frequency section; set to be equal to the difference frequency between the transmitting frequency and the receiving frequency; an oscillator that generates a signal of the difference frequency; a part of the output signal from the transmitting high frequency section to the transmitting antenna; and an output signal of the oscillator. a first mixer that mixes the signals to form a reception frequency signal; a first switch that switches between the output signal of the first mixer and the reception signal from the reception antenna and outputs it to the reception high frequency section; a second mixer that mixes a part of the output signal from the intermediate frequency section to the transmission high frequency section and the output signal of the oscillator to form a reception intermediate frequency signal; an output signal of the second mixer and the reception A second circuit that switches one of the output signals of the high frequency section and outputs it to the receiving intermediate frequency section.
A wireless transmitting/receiving device comprising: a switch; (2) In a radio transmitting/receiving device comprising: a transmitter including a transmitting intermediate frequency section and a transmitting high frequency section; and a receiver including a receiving high frequency section and a receiving intermediate frequency section; a difference frequency set to be equal to the difference frequency between the transmitting frequency and the receiving frequency; an oscillator that generates a signal of the difference frequency; a part of the output signal from the transmitting high frequency section to the transmitting antenna and a portion of the output signal from the transmitting intermediate frequency section. a first switch that switches between and outputs a part of the output signal to the transmission high frequency section; a signal of the reception frequency and a signal of the reception intermediate frequency that mix the output signal of the first switch and the output signal of the oscillator; a mixer that receives the output signal of the mixer and switches between a reception frequency signal and a reception intermediate frequency signal and outputs the signal; a reception signal from the reception antenna and the second switch; a third switch that switches between an output signal of a reception frequency signal and outputs it to the reception high frequency section; a third switch that switches between an output signal of the reception high frequency section and a reception intermediate frequency signal that is an output signal of the second switch; A wireless transmitting/receiving device comprising: a fourth switch for outputting to the receiving intermediate frequency section;