WO2012008197A1

WO2012008197A1 - Transmitter-receiver apparatus

Info

Publication number: WO2012008197A1
Application number: PCT/JP2011/060030
Authority: WO
Inventors: 伊東　正治; 直行折橋
Original assignee: 日本電気株式会社
Priority date: 2010-07-13
Filing date: 2011-04-25
Publication date: 2012-01-19
Also published as: JPWO2012008197A1

Abstract

A transmitter-receiver apparatus comprises a plurality of transmitter-receiver blocks including respective phase sync oscillators for generating local oscillation signals used for down-converting respective RF signals received by a plurality of antennas or local oscillation signals used for up-converting baseband signals. The transmitter-receiver apparatus further comprises a loop band detector circuit that detects the difference between the loop bands of the phase sync oscillators included in the respective transmitter-receiver blocks and that generates a control signal used for causing the loop bands of the respective phase sync oscillators to coincide with each other.

Description

Transceiver

The present invention relates to a transmitter / receiver provided with a plurality of transmitter / receiver blocks.

In a wireless communication system, a plurality of antennas are required to realize a spatial diversity method and a beam steering method, and a baseband signal is converted into an RF (Radio Frequency) signal, or an RF signal is converted into a baseband signal. A plurality of transceiver blocks corresponding to each antenna are required.

Generally, in a radio communication system used in a high frequency band such as a millimeter wave band, it is desirable to connect a transceiver block and an antenna with a shortest distance in order to reduce a loss due to wiring. In the space diversity system, since the antennas are arranged apart from each other, the transceiver block is also arranged apart.

In the beam steering system, the number of antennas and the number of transmitter / receiver blocks may be increased in order to increase the gain by the antenna. In that case, if a plurality of transceiver blocks are accommodated in, for example, one IC (Integrated Circuit), there is a problem that the size of the IC becomes too large. Furthermore, in an IC that accommodates many transceiver blocks, the manufacturing yield may be reduced.

In order to avoid such a problem, each transmitter / receiver block is usually formed by an individual IC. Even if each transmitter / receiver block is formed of individual ICs, the LO signal phase is synchronized for each transmitter / receiver block when the LO signal generated by one LO signal (local oscillation signal) source is distributed to each IC. There is a problem that it is difficult to cause the distribution loss to increase. For this reason, in a radio communication system of the spatial diversity method or the beam steering method, a plurality of transmitter / receiver blocks are formed by individual ICs, and LO signal sources are provided in the respective transmitter / receiver blocks, and phase synchronization is performed by these LO signal sources. A configuration for generating each LO signal is adopted.

FIG. 1 shows a configuration example of a background art receiving apparatus including two receiver blocks 1a and 1b.

The receiving apparatus shown in FIG. 1 has two receiver blocks 1a and 1b, two

antennas

2a and 2b, and a signal source 5 that oscillates a signal having a constant frequency with high stability.

The receiver block 1a includes a low-noise amplifier 3a, a mixer 4a, and a phase-locked oscillator (hereinafter referred to as PLO (Phase Locked Oscillator)) 6a which is an LO signal source. The receiver block 1b includes a low noise amplifier 3b, a mixer 4b, and a PLO 6b. A well-known PLL (Phase Locked Loop) circuit is used for the PLOs 6a and 6b. The PLO (PLL circuit) used in the wireless communication system is also described in Patent Document 1 and Patent Document 2, for example.

In such a configuration, the RF signals received by the

antennas

2a and 2b are amplified by the

low noise amplifiers

3a and 3b. The PLOs 6a and 6b generate LO signals whose phases are synchronized with the signals output from the signal source 5, respectively. The RF signals output from the

low noise amplifiers

3a and 3b are mixed with the LO signals generated by the PLOs 6a and 6b and down-converted by the

mixers

4a and 4b. The signals output from the two

mixers

4a and 4b are combined on the wiring path and output from the output terminal 7 as a baseband signal.

2 shows a signal waveform (130 MHz) of a baseband signal appearing at the output terminal 7 when an RF signal (sine wave) of 60.61 GHz is input to the receiving apparatus shown in FIG. 1 (the frequency of the LO signal is 60.48 GHz). Sine wave) measurement results. As shown in FIG. 2, it can be seen that the output signal (baseband signal) of the receiving apparatus shown in FIG. 1 has a large jitter and contains many unnecessary frequency components.

In order to reduce the jitter of the baseband signal output from the receiving device, PLOs 6a and 6b having sufficiently small phase noise may be used. However, it is still difficult to realize an LO signal source that can be used in a high frequency band such as a millimeter wave band and has sufficiently small phase noise.

JP 2003-78410 A JP 2007-251571 A

Therefore, the present invention provides a transmitter / receiver that includes a plurality of transmitter / receiver blocks and can reduce jitter of a signal obtained by synthesizing the output signals of the transmitter / receiver blocks even in a high frequency band where an LO signal source with sufficiently small phase noise cannot be realized. The purpose is to provide.

In order to achieve the above object, the transmitting / receiving apparatus of the present invention generates a phase oscillation signal for generating a local oscillation signal for down-converting each RF signal received by a plurality of antennas or a local oscillation signal for up-converting a baseband signal. A plurality of transceiver blocks with oscillators;
A loop band detection circuit that detects a difference in loop band of the phase-locked oscillator provided for each transceiver block and generates a control signal for matching the loop band of the phase-locked oscillator; and
Have

FIG. 1 is a block diagram illustrating a configuration of a background art receiving apparatus including a plurality of receiver blocks. FIG. 2 is a waveform diagram illustrating an example of a signal waveform of a baseband signal output from the receiving apparatus illustrated in FIG. FIG. 3 is a graph showing the frequency spectrum of the output signal of each receiver block included in the receiving apparatus shown in FIG. FIG. 4 is a graph showing a state when the frequency spectrums of the output signals of the respective receiver blocks included in the receiving apparatus shown in FIG. 1 are matched. FIG. 5 is a waveform diagram showing an example of a signal waveform of a baseband signal output from the receiving apparatus in the state shown in FIG. FIG. 6A is a diagram illustrating a configuration example of the transmission / reception device according to the first embodiment, and is a block diagram illustrating an overall configuration of the reception device. FIG. 6B is a block diagram illustrating a configuration example of the PLO illustrated in FIG. 6A. FIG. 7A is a block diagram showing another configuration example of the PLO shown in FIG. 6A. FIG. 7B is a circuit diagram showing a configuration example of the loop filter shown in FIG. 7A. FIG. 8 is a block diagram illustrating a configuration example of the loop band detection circuit illustrated in FIG. 6A. FIG. 9 is a block diagram illustrating a configuration example of the PLO for improving the detection sensitivity of the power sensor illustrated in FIG. FIG. 10 is a block diagram illustrating a configuration example of the receiving apparatus according to the second embodiment.

Next, the present invention will be described with reference to the drawings.

FIG. 3 shows frequency spectra of output signals of the respective receiver blocks 1a and 1b when the two receiver blocks 1a and 1b provided in the receiving apparatus shown in FIG. 1 are individually operated.

As shown in FIG. 3, in the receiving apparatus shown in FIG. 1, the frequency spectrum of the output signal of the receiver block 1a is significantly different from the frequency spectrum of the output signal of the receiver block 1b. This is because the phase noises output from the PLOs 6a and 6b are different due to the performance variations of the PLOs 6a and 6b, which are PLL circuits, in particular, the loop bands of the PLO 6a and the PLO 6b are different.

FIG. 4 shows a state when the frequency spectra of the output signals of the two receiver blocks 1a and 1b shown in FIG. 1 are matched. FIG. 5 shows the signal waveform of the baseband signal output from the receiving apparatus when the frequency spectra of the receiver blocks 1a and 1b are matched as shown in FIG. FIG. 4 shows the result of adjustment to widen the loop band of the PLO (PLL circuit) 6a in order to match the frequency spectrum of the output signal of the reception block 1b with the frequency spectrum of the output signal of the reception block 1a. Yes.

As shown in FIG. 5, when the frequency spectrums of the output signals of the receiver blocks 1a and 1b are matched, the loop band of the receiver block 1a is widened and adjusted in the direction in which the phase noise is worsened. The jitter of the baseband signal output from the receiving device is reduced. Such a phenomenon is considered not to occur if PLOs 6a and 6b having sufficiently small phase noise are used. However, as described above, an LO signal source having sufficiently small phase noise that can be used in a high frequency band such as a millimeter wave band is used. It is still difficult to realize. The reason why such a phenomenon occurs is not clear, but it can be attributed to the fact that the origins of the phase noise of the two PLOs 6a and 6b are the same when analogized from the viewpoint of the phenomenon.

The phase noise of the LO signal includes (1) fluctuation of a reference frequency of a crystal oscillator, (2) fluctuation of a power supply voltage supplied from an external power supply, (3) jitter existing in a PLL circuit such as a phase comparator, (4 ) Generated by thermal noise or 1 / f noise of the voltage controlled oscillator of the PLL circuit. Of these, (1) and (2) are considered to have the same influence on a plurality of PLOs, that is, the same origin of phase noise. Of the jitters pointed out in (3), there is no correlation with random jitter, but there is a case where there is a correlation with regular jitter called deterministic jitter. That is, the phase noise of LO signals generated by a plurality of PLOs may be synchronized.

When the phase noise of the LO signals generated by a plurality of PLOs is synchronized, the LO signals generated by the respective PLOs are similarly modulated by the phase noise when the loop bands are matched. Therefore, it is considered that the jitter (fluctuation) of the baseband signal that is a signal obtained by synthesizing the output signals of the plurality of receiver blocks is reduced.

Therefore, in a receiving apparatus that includes a plurality of receiver blocks and that is used in a high frequency band where an LO signal source with sufficiently small phase noise cannot be realized, it is desirable to match the loop bands of the PLOs included in each receiver block.

Note that even in a transmission device including a plurality of transmitter blocks, radio waves (RF signals) radiated from the plurality of transmitter blocks via the antenna are combined in space, and the combined radio waves are received by the receiving antenna. To come. For this reason, it is desirable to match the loop band of the PLO included in each transmitter block in the transmission apparatus including a plurality of transmitter blocks as in the reception apparatus.
(First embodiment)
6A and 6B are block diagrams illustrating a configuration example of the transmission / reception apparatus according to the first embodiment.

FIG. 6A shows the overall configuration of the receiving apparatus, and FIG. 6B shows an example of the configuration of the PLO shown in FIG. 6A. 7A is a block diagram showing another configuration example of the PLO shown in FIG. 6A, and FIG. 7B is a circuit diagram showing a configuration example of the loop filter shown in FIG. 7A.

As shown in FIG. 6A, the receiving apparatus includes two receiver blocks 1a and 1b, two

antennas

2a and 2b, and a signal source that oscillates a signal having a constant frequency (hereinafter referred to as a reference signal) with high stability. 5 and a loop band detection circuit 16 that detects a difference between the loop bands of the PLOs included in the receiver blocks 1a and 1b and adjusts the loop bands to coincide with each other.

The receiver block 1a includes a low noise amplifier 3a, a mixer 4a, and a PLO 6a. The receiver block 1b includes a low noise amplifier 3b, a mixer 4b, and a PLO 6b.

In such a configuration, the signals received by the

antennas

2a and 2b are amplified by the

low noise amplifiers

3a and 3b. The PLOs 6a and 6b generate LO signals whose phases are synchronized with the reference signal output from the signal source 5, respectively. The output signals of the

low noise amplifiers

3a and 3b are mixed by the LO signals generated by the PLOs 6a and 6b with the

mixers

4a and 4b and down-converted. The signals output from the

mixers

4a and 4b are combined in the wiring path and output from the output terminal 7 as a baseband signal.

As shown in FIG. 6B, each of the PLOs 6a and 6b includes a voltage controlled oscillator 8, a frequency divider (DIV) 9, a phase comparator (PFD) 10, a charge pump (CP) 11, and a loop filter 12, respectively. This is a PLL (Phased Locked Loop) circuit. FIG. 6B shows an example in which a low-pass filter (LPF) is used as the loop filter 12. FIG. 6B shows a configuration example for adjusting the loop bandwidth of the PLOs 6a and 6b by changing the output current amount of the charge pump (CP) 11.

The reference signal generated by the signal source 5 is input to the phase comparator 10 via the input terminal 13. The phase comparator 10 compares the phase of the reference signal with the phase of the output signal of the frequency divider 9 and outputs a signal corresponding to the phase difference between them. The charge pump 11 outputs a current having a value corresponding to the output signal of the phase comparator 10. The loop filter 12 converts the output current of the charge pump 11 into a voltage signal and blocks a high frequency signal component of the voltage signal. The voltage controlled oscillator 8 oscillates a signal having a frequency corresponding to the input voltage. The frequency divider 9 divides the oscillation frequency of the voltage controlled oscillator 8 and feeds it back to the phase comparator 10.

In such a configuration, the feedback loop operates so that the frequency of the reference signal matches the frequency of the output signal of the frequency divider 9. Therefore, an LO signal having a desired frequency can be obtained from the voltage controlled oscillator 8 based on the frequency of the reference signal and the frequency division ratio of the frequency divider 9. The LO signal output from the voltage controlled oscillator 8 is output from the output terminal 14.

The loop bands of the PLOs 6a and 6b are determined by the gain of the phase comparator 10, the output current amount of the charge pump 11, and the band of the loop filter 12. The LO signals generated by the PLOs 6a and 6b are input to the loop band detection circuit 16, respectively.

The loop band detection circuit 16 detects a difference between the loop bands of the PLOs 6a and 6b from the LO signals generated by the PLOs 6a and 6b, and supplies a control signal for matching the loop bands to the PLOs 6a and 6b. The loop band detection circuit 16 matches the loop bands of the PLOs 6a and 6b by changing the amount of current of the charge pump 11 included in the PLOs 6a and 6b, for example, by changing the voltage applied to the current source, according to the control signal. Let

Specifically, when it is detected that the loop band of the PLO 6a is wider than the PLO 6b based on the LO signals input from the PLOs 6a and 6b, the loop band detection circuit 16 uses the control signal to charge the PLO 6a. The current amount of the pump 11 is decreased or the current amount of the charge pump 11 of the PLO 6b is increased. In this way, the loop band detection circuit 16 matches the loop bands of the PLOs 6a and 6b that generate the LO signal. As a result, the jitter of the baseband signal output from the output terminal 7 of the receiving device is reduced.

As described above, the loop band of the PLOs 6a and 6b can be adjusted by changing the filter characteristics of the loop filter 12. For example, as shown in FIG. 7B, as the loop filter 12, a low-pass filter including

capacitive elements

19a and 19b whose capacitance value can be changed by an input voltage or a resistive element 20 whose resistance value can be changed by an input voltage. Constitute. In this case, the loop band detection circuit 16 may match the loop bands of the PLOs 6a and 6b by changing the capacitance values of the

capacitive elements

19a and 19b or the resistance value of the resistive element 20 according to the control signal. In that case, the PLOs 6a and 6b have the configuration shown in FIG. 7A.

The loop band detection circuit 16 can be realized, for example, with the configuration shown in FIG.

FIG. 8 is a block diagram showing an example of the configuration of the loop band detection circuit shown in FIG. 6A.

As shown in FIG. 8, the loop band detection circuit 16 includes a mixer 21, a power sensor 22 that detects a power value of a signal output from the mixer 21, and a control unit 28.

The LO signals generated by the PLOs 6a and 6b are input to the mixer 21 via the

input terminals

23a and 23b. The signal output from the mixer 21 is the difference between the LO signals generated by the PLOs 6a and 6b, and becomes a frequency spectrum having a peak in the low frequency region (usually several MHz or less). Here, in the high frequency region of the signal output from the mixer 21, the power value of the difference in phase noise power at the high detuning frequency of the voltage controlled oscillator 8 provided in the PLOs 6a and 6b appears. However, since the phase noise power of the voltage controlled oscillator 8 is originally very small and the power value of the difference between the phase noise powers is also small, this value need not be considered.

Therefore, it can be considered that the power value of the signal output from the mixer 21 is equal to the difference between the loop bands of the PLOs 6a and 6b. Therefore, if the control signal is supplied to the PLOs 6a and 6b so that the power value (detected value) detected by the power sensor 22 is minimized, the loop bands of the PLOs 6a and 6b can be made to substantially coincide.

The control unit 28 generates a control signal for adjusting the loop band of the PLOs 6a and 6b so as to minimize the detection value of the power sensor 22, and outputs the control signal from the

output terminals

24a and 24b. The control unit 28 may be any circuit as long as the detection value of the power sensor 22 can be arithmetically processed, and includes a combinational circuit, a sequential circuit, a DSP, a CPU, an FPGA, a memory, an A / D converter, a D / A converter, and the like. It can be realized by a known information processing apparatus.

The control signal generation method by the control unit 28 includes the following methods.

First, a control signal for expanding one of the PLOs 6a and 6b is output, and a change in the detection value of the power sensor 22 is observed. For example, a control signal for expanding the loop band of the PLO 6a is output from the output terminal 24a.

Here, when the detection value of the power sensor 22 becomes large, the control unit 28 reduces the loop band of the PLO (in this case, PLO 6a) that has been changed until the detection value of the power sensor 22 becomes sufficiently small. A control signal for narrowing is output. Alternatively, a control signal for widening the loop band of the PLO that has not been changed first (in this case, PLO 6b) is output.

On the other hand, when the detection value of the power sensor 22 becomes small, the control unit 28 increases the loop bandwidth of the PLO (in this case, PLO 6a) that has been changed until the detection value of the power sensor 22 becomes sufficiently small. Outputs a control signal for spreading. Alternatively, a control signal for narrowing the loop band of the PLO that has not been changed first (in this case, PLO 6b) is output.

Here, when the detection sensitivity of the power sensor 22 included in the loop band detection circuit 16 is not so high, the detection sensitivity can be improved by the following method.

For example, as shown in FIG. 9, one end of the switch 25 is connected to a connection node between the phase comparators 10 of the PLOs 6 a and 6 b and the charge pump 11, and the other end of the switch 25 is connected to the input terminal 26.

Then, when adjusting the loop band of the PLOs 6a and 6b, the control unit 28 inputs a pilot signal from the input terminal 26 and makes the switch 25 conductive. The frequency of the pilot signal is set to a frequency slightly higher than at least one of the loop bands of the PLOs 6a and 6b.

When a pilot signal is input to the PLOs 6a and 6b, a peak appears at a frequency separated from the center frequency by the frequency of the pilot signal in the frequency spectrum of the LO signal generated by the PLOs 6a and 6b. The level of the peak due to the pilot signal differs depending on the difference between the frequency of the loop band of the PLOs 6a and 6b and the frequency of the pilot signal. That is, since the difference between the loop bands of the PLOs 6a and 6b appears as a peak value, if the peak value is detected using the power sensor 22, the difference between the loop bands of the PLOs 6a and 6b can be detected. Therefore, if an appropriate (relatively large power) pilot signal is input to the PLOs 6a and 6b, it is possible to compensate for the lack of sensitivity of the power sensor 22, and the difference in the loop bandwidth of the PLOs 6a and 6b can be easily detected.

In the present embodiment, the configuration and method for matching the loop bandwidth of the PLO included in each receiver block have been described using the receiver as an example. However, in the configuration illustrated in FIG. 6A, the low noise amplifier 3a, Instead of 3b, if a power amplifier for supplying the RF signals output from the

mixers

4a and 4b to the

antennas

2a and 2b is provided, and an up-conversion mixer is used as the

mixers

4a and 4b, the technique shown in this embodiment is The present invention can also be applied to a transmission apparatus having a plurality of transmitter blocks having a PLO.

Further, in the present embodiment, the configuration example in which the receiver includes the two receiver blocks 1a and 1b has been described. However, the number of receiver blocks is not limited to two, and three or more receiver blocks are provided. May be. In that case, using the same method as described above, the PLO loop band included in any one of the receiver blocks is used as a reference, and the PLO loop band included in the other receiver block is determined as the reference PLO loop band. Should be matched to each.

According to this embodiment, the loop band detection circuit 16 can match the loop bands of the PLOs 6a and 6b included in the receiver blocks 1a and 1b. Therefore, in a receiving device including a plurality of receiver blocks, jitter of the signal waveform of the baseband signal can be reduced even in a high frequency band where an LO signal source with sufficiently small phase noise cannot be realized.

Similarly, in a transmission device including a plurality of transmitter blocks, jitter of an RF signal synthesized in space can be reduced even in a high frequency band where an LO signal source with sufficiently small phase noise cannot be realized.
(Second Embodiment)
FIG. 10 is a block diagram illustrating a configuration example of the receiving apparatus according to the second embodiment.

As shown in FIG. 10, the receiving apparatus according to the second embodiment includes a jitter detection circuit 27 that detects the power of the jitter component of the baseband signal that is output from the receiver blocks 1a and 1b and is synthesized. The bandwidth detection circuit 16 is different from the reception device shown in the first embodiment in that the loop bandwidth of the PLO included in each receiver block is adjusted in consideration of the power of the jitter component detected by the jitter detection circuit 27. ing. Since other configurations and operations are the same as those of the receiving apparatus according to the first embodiment, description thereof is omitted. Since the second embodiment is configured to detect the power of the jitter component of the baseband signal, it can be applied only to the receiving apparatus.

As described above, the jitter of the baseband signal output from the receiving device largely depends on the relationship of the loop bandwidth of the PLO included in each receiver block. However, in order to further reduce the jitter, it is necessary to further reduce the phase noise of the LO signal generated by each PLO. That is, it is preferable that the loop bandwidth of each PLO is as narrow as possible.

Thus, in the second embodiment, the power of the jitter component detected by the jitter detection circuit 27 is minimized while the loop band detection circuit 16 adjusts the loop bands of the PLOs 6a and 6b to coincide. Further, the loop band of the PLOs 6a and 6b is further adjusted.

The jitter detection circuit 27 may acquire the power of the jitter component included in the baseband signal by using, for example, the following methods (1) to (3).
(1) A jitter component is extracted from the baseband signal output from the receiving device by filtering, and the power of the extracted jitter component is measured by a power sensor.
(2) A jitter component is extracted from the baseband signal output from the receiving device by FFT processing, and the power of the extracted jitter component is measured by a power sensor.
(3) The power of the output signal of the receiver block 1a and the power of the output signal of the receiver block 1b are respectively measured by the power sensor, and a first detection value obtained by adding these values is obtained. Further, the second detection value obtained by measuring the power of the baseband signal output from the receiving apparatus, that is, the power of the signal output from the receiver blocks 1a and 1b and synthesized by the wiring path, with the power sensor is acquired. And the electric power of a jitter component is acquired by calculating | requiring the difference of a 1st detection value and a 2nd detection value.

The jitter detection circuit 27 executes the above filter processing, FFT processing, arithmetic processing, and the like in addition to the power sensor. Combination circuit, sequential circuit, DSP, CPU, FPGA, memory, A / D converter, D / A conversion This can be realized by a well-known information processing apparatus equipped with a container.

According to the receiving apparatus of the second embodiment, the jitter band 27 is adjusted by the loop band detection circuit 16 so that the loop bands of the PLOs 6a and 6b match, and the jitter component power included in the baseband signal is detected by the jitter detection circuit 27. Since the loop band of the PLOs 6a and 6b is adjusted so that the power of the jitter component is minimized, the jitter of the signal waveform of the baseband signal can be reduced as compared with the receiving apparatus of the first embodiment.

As mentioned above, although this invention was demonstrated with reference to embodiment, this invention is not limited to the said embodiment. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

This application claims priority based on Japanese Patent Application No. 2010-158647 filed on July 13, 2010, the entire disclosure of which is incorporated herein.

Claims

A plurality of transceiver blocks including a phase-locked oscillator for generating a local oscillation signal for down-converting RF signals received by a plurality of antennas or a local oscillation signal for up-converting a baseband signal, and
A loop band detection circuit that detects a difference in loop band of the phase-locked oscillator provided for each transceiver block and generates a control signal for matching the loop band of the phase-locked oscillator; and
A transmission / reception device having
The loop band detection circuit includes:
A mixer circuit for mixing local oscillation signals generated by the two phase-locked oscillators;
A power sensor for detecting a power value of a signal output from the mixer circuit;
A control unit that generates the control signal so that the power value detected by the power sensor is minimized;
The transmitting / receiving apparatus according to claim 1.
The phase-locked oscillator is
A PLL circuit including a voltage controlled oscillator, a phase comparison circuit, a charge pump and a loop filter,
The loop band detection circuit includes:
The transmission / reception apparatus according to claim 1 or 2, wherein a loop band for each phase-locked oscillator is matched by changing an amount of current output from the charge pump by the control signal.
The phase-locked oscillator is
A PLL circuit including a voltage controlled oscillator, a phase comparison circuit, a charge pump and a loop filter,
The loop filter is
A resistance element having a variable resistance value or a capacitance element having a variable capacitance value is provided.
The loop band detection circuit includes:
4. The transmission / reception apparatus according to claim 1, wherein the loop band of each phase-locked oscillator is matched by changing the resistance value or the capacitance value according to the control signal. 5.
The phase-locked oscillator is
A PLL circuit including a voltage controlled oscillator, a phase comparison circuit, a charge pump and a loop filter,
A switch connected to a connection node of the phase comparison circuit and the charge pump;
The loop band detection circuit includes:
When adjusting the loop band, the switch is turned on,
The transmission / reception apparatus according to any one of claims 1 to 4, wherein a pilot signal having a frequency higher than a frequency of a loop band of at least one of the phase-locked oscillators is supplied to the connection node via the switch.
A plurality of receiver blocks each including a phase-locked oscillator that generates a local oscillation signal for down-converting RF signals received by a plurality of antennas;
A jitter detection circuit that detects power of a jitter component included in a baseband signal that is a signal obtained by synthesizing an output signal of the receiver block;
The difference between the loop bands of the phase-locked oscillators provided for each receiver block is detected, the loop bands of the phase-locked oscillators are matched, and the power value of the jitter component detected by the jitter detection circuit is minimized. A loop band detection circuit for generating a control signal,
A receiving apparatus.