Bidirectional amplifier module and adjustment method

Abstract

To adjust the RF output level to a predetermined output level without degrading the RF signal used for transmission. [Solution] The system comprises an antenna-side terminal, a main unit-side terminal, a signal amplification circuit provided between the antenna-side terminal and the main unit-side terminal and capable of adjusting the amplification of the RF signal for transmission, a state detection means for detecting whether it is in a transmission state or a reception state, an output level detection means for detecting the RF output level of the antenna, and a control unit for switching the transmission and reception state of the signal amplification circuit. The control unit acquires the RF output level from the output level detection means when the transmission state is detected by the state detection means, and when the state detection means detects that the system has transitioned from the transmission state to the reception state, after a predetermined waiting time has elapsed, the state detection means checks whether the detection of the reception state is continuing, and if it is confirmed that the detection of the reception state is continuing, the amplification of the RF signal for transmission is adjusted based on the acquired RF output level.

Description

Technical Field

[0001] The present invention relates to a bidirectional amplifier module and an adjustment method.

Background Art

[0002] In Patent Document 1 below, in an amplifier module provided between an antenna and a main body, a technique is disclosed in which an attenuator connected in series to a PA (Power Amplifier) attenuates the signal level of a transmission signal to an appropriate predetermined level.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, since the technique of Patent Document 1 cannot control the attenuator, when the signal level of the transmission signal fluctuates, the signal level of the transmission signal cannot be made constant. Further, in the technique of Patent Document 1, when the attenuator is controlled while the transmission signal is being transmitted, there is a risk of degrading the transmission signal.

Means for Solving the Problems

[0005] A bidirectional amplifier module according to one embodiment includes an antenna-side terminal connected to an antenna, a main unit-side terminal connected to the main unit, a signal amplification circuit provided between the antenna-side terminal and the main unit-side terminal and capable of adjusting the amplification of the RF signal for transmission, a state detection means for detecting whether the state is transmitting or receiving, an output level detection means for detecting the RF output level of the antenna, and a control unit for switching the transmit and receive state of the signal amplification circuit. The control unit acquires the RF output level from the output level detection means when the state detection means detects the transmission state, and when the state detection means detects that the state has transitioned from the transmission state to the reception state, after a predetermined waiting time has elapsed, the state detection means checks whether the detection of the reception state is continuing, and if it is confirmed that the detection of the reception state is continuing, it adjusts the amplification of the RF signal for transmission based on the acquired RF output level. [Effects of the Invention]

[0006] According to one embodiment of the bidirectional amplifier module, the RF output level can be adjusted to a predetermined output level without degrading the transmitted RF signal. [Brief explanation of the drawing]

[0007] [Figure 1] A diagram showing the configuration of a bidirectional amplifier module according to one embodiment. [Figure 2] A flowchart showing an example of the processing procedure by the control unit of a bidirectional amplifier module according to one embodiment. [Figure 3] Timing chart showing an example of attenuator adjustment timing in a bidirectional amplifier module according to one embodiment. [Modes for carrying out the invention]

[0008] An embodiment will be described below with reference to the drawings.

[0009] (Configuration of the bidirectional amplifier module 100) Figure 1 shows the configuration of a bidirectional amplifier module 100 according to one embodiment. The wireless communication system 10 shown in Figure 1 is mounted on a vehicle such as an automobile in order to realize both C-V2X (Cellular V2X) communication and DSRC (Dedicated Short Range Communication) communication. As shown in Figure 1, the wireless communication system 10 comprises an antenna 11, a main unit 12, and a bidirectional amplifier module 100.

[0010] The bidirectional amplifier module 100 includes an antenna-side terminal 101, a main unit-side terminal 102, a signal amplification circuit 110, an RF (Radio Frequency) detector 104, a control unit 105, an antenna detection circuit 106, an HPF (High Pass Filter) 107, a power supply circuit 108, and an LPF (Low Pass Filter) 109.

[0011] The antenna-side terminal 101 is connected to the antenna 11 via cable 13A and transmits and receives RF signals to and from the antenna 11. The main unit-side terminal 102 is connected to the main unit via cable 13B and transmits and receives RF signals to and from the main unit 12.

[0012] The signal amplification circuit 110 is provided between the antenna-side terminal 101 and the main unit-side terminal 102, and amplifies the RF signals transmitted and received to the antenna 11. The signal amplification circuit 110 includes a switch 111 provided on the antenna-side terminal 101 side, a switch 112 provided on the main unit-side terminal 102 side, a transmit amplifier PA and a receive amplifier LNA provided in parallel between switches 111 and 112, an attenuator ATT, and an output level detector 113. The transmit amplifier PA amplifies the RF signal for transmission. The receive amplifier LNA amplifies the RF signal for reception. The attenuator ATT is connected in series with the transmit amplifier PA and adjusts the amplification of the RF signal for transmission by the transmit amplifier PA. The output level detector 113 is an example of an "output level detection means" and detects the RF output level of the antenna 11.

[0013] The RF detector 104 is an example of a "state detection means" and detects the transmission and reception status of RF signals. Specifically, the RF detector 104 detects whether a transmission RF signal is being transmitted to the antenna 11 (hereinafter referred to as the "transmission state") or whether a reception RF signal has been received from the antenna 11 (hereinafter referred to as the "reception state").

[0014] The control unit 105 switches the transmission and reception state of the signal amplification circuit 110.

[0015] For example, when the RF detector 104 detects a transmission state, the control unit 105 switches switches 111 and 112 to the transmit amplifier PA side, thereby switching the signal amplification circuit 110 to a state in which the transmit RF signal is amplified by the transmit amplifier PA.

[0016] Furthermore, when the RF detector 104 detects a reception state, the control unit 105 switches switches 111 and 112 to the receiving amplifier LNA side, thereby switching the signal amplification circuit 110 to a state in which the receiving amplifier LNA amplifies the RF signal for reception.

[0017] Furthermore, the control unit 105 can adjust the amplification level of the RF signal for transmission by the transmitting amplifier PA by controlling the attenuator ATT provided in the signal amplification circuit 110.

[0018] In particular, the control unit 105 can adjust the RF output level of the antenna 11 to a predetermined output level (for example, +23 dBm) by adjusting the attenuator ATT according to the RF output level of the antenna 11 detected by the output level detector 113, thereby adjusting the amplification of the transmitted RF signal.

[0019] The control unit 105 is, for example, a device (such as a microcontroller) equipped with a processor, memory, etc., and the processor executes a program stored in the memory to realize each function of the control unit 105.

[0020] The antenna detection circuit 106 detects the state of the antenna 11.

[0021] The HPF 107 is provided between the body-side terminal 102 and the signal amplification circuit 110. By not allowing the DC power input from the body-side terminal 102 to pass through, the DC power is prevented from being supplied to the signal amplification circuit 110.

[0022] The power supply circuit 108 uses the DC power input from the body-side terminal 102 to supply DC power to each part of the bidirectional amplifier module 100 through a power supply line (not shown).

[0023] The LPF 109 is provided between the body-side terminal 102 and the power supply circuit 108. By not allowing the RF signal input from the body-side terminal 102 to pass through, the RF signal is prevented from being supplied to the power supply circuit 108.

[0024] (An example of the processing procedure by the control unit 105) FIG. 2 is a flowchart showing an example of the processing procedure by the control unit 105 provided in the bidirectional amplifier module 100 according to an embodiment.

[0025] First, the control unit 105 determines whether the transmission / reception state of the RF signal detected by the RF detector 104 has changed from the reception state to the transmission state (step S201).

[0026] If it is determined in step S201 that the state has not changed from the reception state to the transmission state (step S201: NO), the control unit 105 executes step S201 again.

[0027] If it is determined in step S201 that the state has changed from the reception state to the transmission state (step S201: YES), the control unit 105 acquires the current RF output level of the antenna 11 from the output level detector 113 (step S202: RF output level acquisition step).

[0028] Next, the control unit 105 determines whether the transmission / reception state of the RF signal detected by the RF detector 104 has transitioned from the transmission state to the reception state (step S203).

[0029] If it is determined in step S203 that the system has not transitioned from the transmission state to the reception state (step S203: NO), the control unit 105 returns to step S202.

[0030] In step S203, if it is determined that the state has transitioned from transmission to reception (step S203: YES), the control unit 105 waits for a predetermined waiting time (for example, 100 μs) (step S204), and then determines whether the transmission and reception state of the RF signal detected by the RF detector 104 is continuing to be in the reception state (step S205: confirmation step).

[0031] If it is determined in step S205 that the reception state is not continuing (step S205: NO), the control unit 105 returns to step S202.

[0032] In step S205, if it is determined that the reception state is continuing (step S205: YES), the control unit 105 calculates the amount of adjustment of the attenuator ATT necessary to bring the RF output level of the antenna 11 to a predetermined output level (for example, +23 dBm) based on the RF output level acquired in step S202 (step S206: adjustment step).

[0033] Then, the control unit 105 adjusts the attenuator ATT by the adjustment amount calculated in step S206 (step S207). This allows the control unit 105 to adjust the RF output level of the antenna 11 to a predetermined output level (for example, +23 dBm).

[0034] Subsequently, the control unit 105 completes the series of processes shown in Figure 2. By repeatedly executing the series of processes shown in Figure 2, the control unit 105 can maintain the RF output level of the antenna 11 at a predetermined output level (for example, +23 dBm) even if the RF output level of the antenna 11 fluctuates.

[0035] Furthermore, it is preferable that the predetermined waiting time is longer than the minimum data transmission interval of the RF signal to be transmitted. For example, if the minimum data transmission interval is 80 μs, it is preferable that the predetermined waiting time be longer than 80 μs (for example, 100 μs). This allows the control unit 105 to adjust the attenuator ATT if the transmission of the next RF signal to be transmitted has not started after the minimum data transmission interval has elapsed, and to not adjust the attenuator ATT if the transmission of the next RF signal to be transmitted has started after the minimum data transmission interval has elapsed.

[0036] (An example of attenuator (ATT) adjustment timing) Figure 3 is a timing chart showing an example of the adjustment timing of the attenuator (ATT) in a bidirectional amplifier module 100 according to one embodiment.

[0037] Figure 3(a) shows the adjustment timing of the attenuator ATT by the control unit 105 when a C-V2X format RF signal for transmission is transmitted during the first transmission cycle.

[0038] Figure 3(b) shows the adjustment timing of the attenuator ATT by the control unit 105 when a C-V2X format RF signal for transmission is transmitted during the first, second, and third transmission cycles.

[0039] Figure 3(c) shows the adjustment timing of the attenuator ATT by the control unit 105 when a C-V2X format RF signal for transmission is transmitted during the first and third transmission cycles.

[0040] Figure 3(d) shows the adjustment timing of the attenuator ATT by the control unit 105 when a C-V2X format RF signal for transmission is transmitted during the first and fourth transmission cycles.

[0041] As shown in Figures 3(a) to 3(d), after the transmission of the RF signal for transmission is completed (i.e., after switching from "transmission state" to "reception state"), if the "reception state" continues after a predetermined waiting time has elapsed (i.e., the transmission of the next RF signal for transmission has not yet started), the control unit 105 starts adjusting the attenuator ATT.

[0042] In particular, in the examples shown in Figures 3(a) to 3(d), the control unit 105 sets the predetermined waiting time to 100 μs, which is longer than 80 μs, because the minimum data transmission interval for the RF signal for transmission in C-V2X format is 80 μs.

[0043] As a result, the control unit 105 can adjust the attenuator ATT only if, after the transmission of the RF signal for transmission is completed in one transmission cycle, the RF signal for transmission is not transmitted in the next transmission cycle. In other words, the control unit 105 can avoid the transmission of the RF signal for transmission and the adjustment of the attenuator ATT being performed simultaneously, thereby suppressing the degradation of the RF signal for transmission.

[0044] For example, in the example shown in Figure 3(a), the control unit 105 can perform adjustment of the attenuator ATT during the second transmission cycle in which the RF signal for transmission is not transmitted, without adjusting the attenuator ATT during the first transmission cycle in which the RF signal for transmission is transmitted.

[0045] Furthermore, for example, in the example shown in Figure 3(b), the control unit 105 can perform adjustment of the attenuator ATT during the 1st, 2nd, and 3rd transmission cycles in which the RF signal for transmission is transmitted, and adjust the attenuator ATT during the 4th transmission cycle in which the RF signal for transmission is not transmitted.

[0046] Furthermore, for example, in the example shown in Figure 3(c), the control unit 105 can perform adjustments to the attenuator ATT during the 1st and 3rd transmission cycles when the RF signal for transmission is transmitted, but not during the 2nd and 4th transmission cycles when the RF signal for transmission is not transmitted.

[0047] Furthermore, for example, in the example shown in Figure 3(d), the control unit 105 can perform adjustment of the attenuator ATT during the 1st and 4th transmission cycles when the RF signal for transmission is transmitted, but not during the 2nd transmission cycle when the RF signal for transmission is not transmitted.

[0048] Furthermore, as shown in Figures 3(a) to 3(d), the control unit 105 starts adjusting the attenuator ATT during the transmission cycle of a certain RF signal, and then finishes adjusting the attenuator ATT before the transmission cycle of the next RF signal begins. This allows the control unit 105 to avoid overlapping transmission of the RF signal and adjustment of the attenuator ATT, thereby suppressing degradation of the RF signal.

[0049] Figure 3(e) shows the timing of the attenuator ATT adjustment by the control unit 105 when a DSRC-format RF signal for transmission is transmitted during the first transmission cycle. In this case as well, the control unit 105 starts adjusting the attenuator ATT after a predetermined waiting time has elapsed since the end of transmission of the DSRC-format RF signal for transmission (i.e., after switching from "transmission state" to "reception state"), if the "reception state" is still in effect (i.e., transmission of the next DSRC-format RF signal for transmission has not yet started).

[0050] As a result, the control unit 105 can adjust the attenuator ATT only if the transmission of the DSRC-format RF signal has finished and no further DSRC-format RF signal has been transmitted.

[0051] In other words, the bidirectional amplifier module 100 according to one embodiment is capable of transmitting and receiving not only RF signals in C-V2X format, but also RF signals in DSRC format.

[0052] Furthermore, the control unit 105 can avoid the overlapping operation of transmitting the DSRC-format RF signal and adjusting the attenuator ATT, thereby suppressing the degradation of the DSRC-format RF signal.

[0053] In the example shown in Figure 3(e), the control unit 105 sets the predetermined waiting time to 100 μs, which is longer than 80 μs, because the minimum data transmission interval for the DSRC-format RF signal is 80 μs.

[0054] Although one embodiment of the present invention has been described in detail above, the present invention is not limited to these embodiments, and various modifications or changes are possible within the scope of the gist of the present invention as described in the claims. [Explanation of Symbols]

[0055] 10 Wireless communication systems 11 Antennas 12 Main body 13A, 13B cable 100 Bidirectional Amplifier Modules 101 Antenna side terminal 102 Main unit side terminal 110 Signal amplification circuit 111,112 switches PA Transmitter Amplifier LNA Receiver Amplifier ATT attenuator 113 Output level detector (output level detection means) 104 RF detector (state detection means) 105 Control Unit 106 Antenna detection circuit 107 HPF 108 Power supply circuit 109 LPF

Claims

1. The antenna terminal that connects to the antenna, The terminal on the main unit that connects to the main unit, A signal amplification circuit is provided between the antenna-side terminal and the main unit-side terminal, and is capable of adjusting the amplification level of the transmitted RF signal. A state detection means for detecting whether the state is transmitting or receiving, An output level detection means for detecting the RF output level of the aforementioned antenna, A control unit that switches the transmission and reception state of the signal amplification circuit and Equipped with, The control unit, When the transmission state is detected by the state detection means, the RF output level is obtained from the output level detection means. If the state detection means detects that the state has transitioned from the transmission state to the reception state, after a predetermined waiting time has elapsed, the state detection means confirms whether the detection of the reception state is continuing. If it is confirmed that the detection of the reception state is continuing, the amplification of the transmission RF signal is adjusted based on the acquired RF output level. A bidirectional amplifier module characterized by the following features.

2. The predetermined waiting time is longer than the minimum data transmission interval of the RF signal for transmission. The bidirectional amplifier module according to feature 1.

3. The predetermined waiting time is longer than the minimum data transmission interval of the C-V2X (Cellular V2X) format RF signal used for transmission. The bidirectional amplifier module according to feature 2.

4. The control unit, After starting to adjust the amplification of the C-V2X format RF signal to be transmitted, the adjustment of the amplification of the C-V2X format RF signal to be transmitted is completed before the next transmission cycle of the C-V2X format RF signal to be transmitted begins. The bidirectional amplifier module according to feature 3.

5. The aforementioned signal amplification circuit is A transmitting amplifier that amplifies the aforementioned RF signal, A receiving amplifier that amplifies the RF signal for reception, An attenuator for adjusting the amplification of the transmitted RF signal and Equipped with, The control unit, The amplification of the RF signal for transmission is adjusted by adjusting the attenuator. The bidirectional amplifier module according to claim 1, characterized in that...

6. A method for adjusting the amplification of a transmission RF signal using a bidirectional amplifier module, which is provided between the main unit and the antenna and can be switched between a transmission state and a reception state, When the transmission state is in place, the RF output level acquisition step involves acquiring the RF output level of the antenna, When the state transitions from the transmission state to the reception state, a confirmation step is taken to check whether the reception state continues after a predetermined waiting time has elapsed. If the continuation of the reception state is confirmed by the verification step, an adjustment step is performed to adjust the amplification of the transmission RF signal based on the acquired RF output level. A method of adjustment characterized by including the following.

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