Amplification equipment

Abstract

To provide a technique for suppressing unnecessary radiation from an amplification device using a carrier control method.SOLUTION: An amplification device includes an amplification circuit that amplifies an input signal, an amplitude limiting circuit that limits the amplitude of the input signal, a switching circuit that switches connection between a path via the amplification circuit and a path via the amplitude limiting circuit, and a switching control circuit that detects the input signal and controls the switching circuit to switch connection from a path via the amplitude limiting circuit to a path via the amplification circuit when the input signal is detected.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an amplifier device, and more particularly to an amplifier device for use in wireless communications. [Background technology]

[0002] A wireless communication device with a relatively low transmission power may be equipped with an external amplifier device that amplifies the transmission power. When the wireless communication device is transmitting, the amplifier device must amplify the transmission signal output from the wireless communication device using an amplifier circuit inside the amplifier device and transmit the amplified signal to the antenna, and when the wireless communication device is receiving, the amplifier device must transmit the reception signal received by the antenna to the wireless communication device via a bypass circuit of the amplifier circuit. Therefore, it is necessary to switch the path inside the amplifier device in conjunction with the transmission and reception of the wireless communication device.

[0003] A technology has been disclosed in which a power amplifier having a signal path switching function is used to switch paths and power supply from a power circuit depending on whether the output level of a transmitter required during transmission is a level that requires a power amplifier or a level that does not require a power amplifier (see Patent Document 1). However, when an external amplifier device that amplifies the transmission power is provided, a separate control line is required to switch paths within the amplifier device in conjunction with transmission and reception of the wireless communication device. In addition, a method of switching paths within the amplifier device in conjunction with transmission and reception of the wireless communication device, known as carrier control, has long existed. The method detects a transmission signal from the wireless communication device and switches paths within the amplifier device. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 11-308125 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when changing the path in the amplifier using the technology described in Patent Document 1, a separate cable for a control signal that controls the amplifier from the wireless communication device is required in addition to the coaxial cable that transmits the wireless signal. Also, in the above-mentioned carrier control method, when changing the path in the amplifier, a cable for a control signal that controls the amplifier from the wireless communication device is not required, but there is a problem in that unnecessary radiation is generated because a momentary interruption in the signal occurs between the time when the wireless communication device starts transmission and the time when transmission is switched to via the amplifier of the amplifier.

[0006] The present invention has been made in view of the above circumstances, and has an object to provide a technique for suppressing unwanted radiation from an amplifier using a carrier control system. [Means for solving the problem]

[0007] In order to solve the above problems, an amplification device according to one embodiment of the present invention is characterized in comprising an amplifier circuit that amplifies an input signal, an amplitude limiting circuit that limits the amplitude of the input signal, a switching circuit that switches a connection between a path via the amplifier circuit and a path via the amplitude limiting circuit, and a switching control circuit that detects the input signal and, when the input signal is detected, controls the switching circuit to switch the connection from the path via the amplitude limiting circuit to the path via the amplifier circuit.

[0008] Any combination of the above components, and any transformation of the present invention into a method, device, system, recording medium, computer program, etc., are also effective as aspects of the present invention. Effect of the Invention

[0009] According to the present invention, it is possible to provide a technique for suppressing unwanted radiation from an amplifier using a carrier control system. [Brief description of the drawings]

[0010] [Figure 1]1 is a schematic diagram of a wireless communication facility to which an amplifier device according to the present invention is connected. [Diagram 2] FIG. 1 is a diagram illustrating the configuration of a carrier control type amplifier circuit. [Diagram 3] FIG. 1 is a configuration diagram of an amplifier device according to the present invention. [Figure 4] 2 is a configuration diagram of an amplitude limiting circuit in the amplifier device of the present invention. [Diagram 5] 4 is a time chart of signals in each part of the amplifier device of the present invention. [Figure 6] FIG. 11 is a configuration diagram of an amplifier device according to a second embodiment of the present invention. [Figure 7] FIG. 11 is a configuration diagram of an amplifier device according to a third embodiment of the present invention. [Figure 8] FIG. 11 is a configuration diagram of an amplitude limiting circuit in an amplifier device according to a third embodiment of the present invention. [Figure 9] FIG. 11 is a configuration diagram of a modified example of an amplitude limiting circuit in the amplifying device according to the third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present invention will be described with reference to the accompanying drawings. Fig. 1 is a schematic diagram of a wireless communication device to which an amplifier is connected. The wireless communication device 100 includes a wireless communication device 1, an amplifier device 2, and an antenna 3.

[0012] In the wireless communication equipment 100, the transmitting / receiving connector of the wireless communication device 1 and the connector (input terminal) of the amplifier 2 are connected by a coaxial cable, and the connector (output terminal) of the amplifier 2 and the connector of the antenna 3 are connected by a coaxial cable. In addition to these, the wireless communication equipment 100 has a power supply unit (not shown) that supplies the necessary power to the wireless communication device 1 and the amplifier 2. Note that the notations of input and output such as input terminal and output terminal are defined with respect to the direction of the transmission signal.

[0013] The wireless communication device 1 is a transceiver that transmits and receives radio frequency waves to communicate various information such as voice, images, location information, etc. Although the figure shows a portable transceiver, it may be an in-vehicle transceiver or an indoor transceiver.

[0014] The amplifier 2 is a device for increasing the transmission output of the wireless communication equipment 100 to a transmission output greater than the transmission output when only the wireless communication device 1 is used for transmission. In detail, the amplifier 2 is a device that amplifies the transmission signal of the wireless communication device 1 and supplies it to the antenna 3. Furthermore, the amplifier 2 has a function of transmitting the reception signal transmitted from the antenna 3 to the wireless communication device 1. The amplifier 2 may also have a function of supplying the transmission signal of the wireless communication device 1 to the antenna 3 without amplifying it.

[0015] The antenna 3 outputs the transmission signal supplied from the amplifier 2 as a radio wave. The antenna 3 also converts the received radio wave into a received signal.

[0016] The amplifier 2 will be described with reference to Fig. 2. Fig. 2 is a configuration diagram of the amplifier 2. The amplifier 2 includes an amplifier circuit 20, a bypass circuit 21, a switching circuit 22 (221, 222), and a switching control circuit 23. The amplifier circuit 20 is an amplifier for amplifying the transmission output signal of the wireless communication device 1 to obtain a transmission output higher than the transmission output of the wireless communication device 1. For example, when the transmission output of the wireless communication device 1 is 5 W, the amplifier circuit 20 amplifies the transmission signal of the wireless communication device 1 to 20 W.

[0017] The bypass circuit 21 is a path for transmitting a received signal from the antenna 3 to the wireless communication device 1. In addition, the bypass circuit 21 may be a path that bypasses the amplifier when the amplification of a transmission signal by the amplifier circuit 20 of the amplifier device 2 is not required, that is, when the signal is output from the antenna 3 with the transmission output of the wireless communication device 1.

[0018] The switching circuit 22 includes an input-side switching circuit 221 for switching between the amplifier circuit 20 and the bypass circuit 21 for the input terminal C1, and an output-side switching circuit 222 for switching between the amplifier circuit 20 and the bypass circuit 21 for the output terminal C2. The input-side switching circuit 221 switches between supplying a transmission signal output from the wireless communication device 1 to the amplifier circuit 20 or to the bypass circuit 21. The output-side switching circuit 222 switches between supplying a transmission signal amplified by the amplifier circuit 20 to an antenna or transmitting a transmission signal of the wireless communication device 1 transmitted via the bypass circuit 21 to the antenna 3. In addition, when transmitting a reception signal from the antenna 3 to the wireless communication device 1, the input-side switching circuit 221 and the output-side switching circuit 222 connect the wireless communication device 1 and the antenna 3 via the bypass circuit 21. Hereinafter, the switching destination of the switching circuit 22 will be referred to as the amplifier circuit side or the bypass circuit side.

[0019] The switching control unit 23 detects a transmission signal output from the wireless communication device 10, and switches the switching circuit 22 to the amplifier circuit side when a transmission signal is detected. In other words, the amplifier 2 switches between transmission and reception in the amplifier 2 by a carrier control method. Although it was said above that a "transmission signal is detected," since it is meaningless for the transmission signal to carry information only on a carrier wave (carrier) during the time required for signal detection, hereafter it may be written as "carrier detection," but the meaning is the same. Also, "reception" refers to the state in which a signal is being received, and the state in which no signal is being received is strictly speaking "standby," but unless otherwise specified, it will be written as "reception."

[0020] The carrier control method uses the carrier of the wireless communication device 1 to switch the path of the amplifier device 2 from the bypass circuit side to the amplifier circuit side. In detail, the carrier control method detects and rectifies a part of the carrier transmitted from the wireless communication device 1 to obtain a DC voltage according to the level of the carrier. Furthermore, the carrier control method switches the switching circuit 21 to the amplifier circuit side when the obtained DC voltage exceeds a predetermined value. The carrier control method is a well-known technology.

[0021] In the carrier control method, when changing the path or operation corresponding to transmission and reception within the amplifier 2, a cable for a control signal to control the amplifier 2 from the wireless communication device 1 is not required, but the following phenomenon occurs.

[0022] (1) During the time until the transmission signal from the wireless communication device 1 is detected, the transmission signal is supplied to the antenna via the bypass circuit 21 that bypasses the amplifier circuit 20, (2) Furthermore, while the transmission signal from the wireless communication device 1 is being supplied to the antenna 3 via the detour circuit 21, the switching control circuit 23 detects the transmission signal and the switching circuit 22 operates, so that the path of the transmission signal is temporarily released from the detour circuit 21, (3) After that, the switching operation of the switching circuit 22 is completed, and the transmission signal from the wireless communication device 1 is supplied to the amplifier circuit 20, and the path is switched to supply the transmission signal amplified by the amplifier circuit 20 to the antenna 3. Therefore, the transmission signal supplied to the antenna 3 is interrupted while the switching circuit 22 switches from the bypass circuit 21 to the amplifier circuit 20. In other words, the transmission signal is momentarily interrupted in the process of starting transmission.

[0023] Therefore, there is a problem that a momentary interruption in the transmission signal occurs between the time when the wireless communication device 1 starts transmission and the time when the transmission is switched to transmission via the amplifier circuit of the amplifier device 2, causing unwanted radiation due to the momentary interruption in the transmission signal.

[0024] The above-mentioned unwanted radiation occurs over a wide band due to the unwanted radiation caused by a momentary interruption of a signal. Also, the greater the power supplied to the antenna 3 immediately before and immediately after the momentary interruption, the greater the level of unwanted radiation. Therefore, in order to suppress unwanted radiation at the start of transmission, it is necessary to reduce the power supplied to the antenna 3 before and after the momentary interruption. Below, a technique for suppressing unwanted radiation during switching by a carrier control method will be described with reference to several embodiments.

[0025] (Embodiment 1) An amplifier device 20 according to a first embodiment of the present invention will be described with reference to Fig. 3. Fig. 3 is a configuration diagram of the amplifier device 20. In contrast to the amplifier device 20 previously described in Fig. 2, the amplifier device 2 according to the first embodiment has an amplitude limiting circuit 24 as a bypass circuit 21, and further includes an amplification control circuit 25 that controls the amplification degree of the amplifier circuit 20.

[0026] The amplifier 2 switches between a transmission state and a standby state by a carrier control method. It detects a carrier from the wireless communication device 1 and switches the path in the amplifier 2 to a transmission path in which the amplifier circuit 20 amplifies and outputs the transmission signal. That is, the switching control circuit 23 detects the carrier, and outputs a path switching signal to the switching circuit 22, which switches the path from the amplitude limiting circuit 24 (detour path) to the amplifier circuit 20 (amplification path). The amplifier 20 transitions to a transmission operation at the rising edge of this path switching signal. When the amplifier 2 starts outputting the path switching signal, it controls the amplification degree of the amplifier circuit 20 by the amplification control circuit 25, and then gradually increases the amplification degree of the amplifier circuit 20 by the amplification control circuit 25, and controls it so that it reaches the normal amplification degree over a predetermined time, and outputs the transmission signal.

[0027] The amplitude limiting circuit 24 is a bypass path for the amplifier circuit 20, and limits the amplitude of a signal transmitted between the input side switching circuit 221 and the output side switching circuit 222. Specifically, the amplitude limiting circuit 24 includes an amplitude limiting element that limits the amplitude of a signal transmitted to a transmission path as shown in FIG. 4. The amplitude limiting element is, for example, a bidirectional diode, and the bidirectional diode is interposed between the ground potential. Thus, the voltage amplitude of the transmitted signal is limited by the forward voltage of the diode. The amplitude limiting element may be two diodes arranged in different directions, and it is preferable that the characteristics of the two diodes are the same. In addition, when the wireless communication device 1 is in a receiving state, the amplitude limiting circuit 24 transmits the reception signal received by the antenna 3 to the wireless communication device 1. Since the voltage amplitude of the received signal is overwhelmingly smaller than the amplitude voltage limited by the amplitude limiting circuit 24 of the amplitude limiting circuit 24, there is no problem with the wireless communication device 1 receiving the signal via the amplitude limiting circuit 24.

[0028] The amplification control circuit 25 controls the amplification degree of the amplification circuit 20 for a predetermined time from the start of transmission. Therefore, the amplification circuit 20 has a gain control function that can change the amplification degree by a predetermined signal. The amplification control circuit 25 outputs an amplification degree control signal to the amplification circuit 20 to change the amplification degree.

[0029] In explaining in detail the operation of the amplifying device 20 according to the first embodiment of the present invention to suppress unwanted radiation during switching by the carrier control method, changes in each signal when the amplifying device 2 starts a transmission operation will be explained using Fig. 5. Fig. 5 is a time chart with the rising edge of the transmission signal outputted when the wireless communication device 1 starts transmitting as the reference "t0", and shows changes in the transmission signal of the wireless communication device 1, changes in the detection signal of the carrier detection in the switching control circuit 23, changes in the path switching signal by the switching control circuit 23, changes in the state of the switching circuit 22, changes in the amplification degree control signal outputted from the amplification control circuit 25, and changes in the transmission signal outputted from the amplifying device 2.

[0030] The wireless communication device 1 starts transmission. When the wireless communication device 1 starts transmission, a transmission signal output from the wireless communication device 1 is input to the amplifier device 2. The transmission signal is transmitted to the antenna 3 by the switching circuit 22 via the amplitude limiting circuit 24. In addition, a part of the transmission signal is input to the switching control circuit 23. As shown in Fig. 5, the carrier amplitude level of the transmission signal of the wireless communication device 1 gradually increases from "t0" at the start of transmission.

[0031] The switching control circuit 23 detects and rectifies the carrier of the transmission signal, and converts it into a detection signal, which is a DC voltage corresponding to the amplitude level of the carrier. The detection signal shown in "switching control circuit / detection signal" in FIG. 5 increases in voltage value because the amplitude level of the carrier increases with time. Furthermore, the switching control circuit 23 compares a predetermined voltage value with the voltage value of the detection signal, and outputs the above-mentioned path switching signal when the voltage value of the detection signal is equal to or higher than the predetermined voltage value. Since it is desirable that the time until the amplifier 2 is in a transmitting state is short, and it is also desirable that the transmission output of the wireless communication device 1 required to set the amplifier 2 in a transmitting state is low, it is desirable that the predetermined voltage value is set low enough to be unaffected by noise. Moreover, the predetermined voltage value is set lower than the detection signal generated by the amplitude level of the carrier whose amplitude level is limited by the amplitude limiting circuit 24 described later.

[0032] The timing at which the switching control circuit 23 outputs the path switching signal is designated as "t1." As described above, at this timing "t1," the amplifier device 2 starts to transition to a transmission state. The path switching signal is transmitted to the switching circuit 22 and the amplifier control circuit 25.

[0033] The switching circuit 221 switches the transmission signal transmitted to the connector C1 from the amplitude limiting circuit 24 to the amplifier circuit 20 by the path switching signal. Also, the switching circuit 222 switches the signal transmitted to the connector C2 from the signal transmitted by the amplitude limiting circuit 24 to the signal transmitted by the amplifier circuit. However, since the switching circuit 22 is not switched instantly by the path switching signal, the switching circuit 221 switches to the connection state (transmission state) with the amplifier device 20 side after the two periods T1 and T2 have elapsed: a period T1 in which the connector C1 side is connected to the amplitude limiting circuit 24 side (reception state) and the period T2 in which the connector C1 side is released and is not connected to either the amplitude limiting circuit 24 side or the amplifier circuit 20 side (release state) in the "switching circuit" in FIG. 5 . Similarly, the switching circuit 222 switches the connector C2 side to the amplifier circuit 20 side after the periods T1 and T2.

[0034] As shown in FIG. 5, the timing when the amplitude level of the carrier of the "wireless communication device-transmission signal" starts to be limited by the amplitude limiting element of the amplitude limiting circuit 24 is "t2". The end timing of the period T1 (the start timing of the period T2) is "t3". The end timing of the period T2 is "t4". From the above, the transmission signal output from the wireless communication device 1 is supplied to the antenna 3 via the amplitude limiting circuit 24 because the switching circuit 22 is in a receiving state from "t0" to "t3". The "amplifier-transmission signal" in FIG. 5 is a change in the amplitude level of the power supplied to the antenna 3, and shows a change in the amplitude level of the power output from the connector C2. The "amplifier-transmission signal" shown in FIG. 5 is smaller than the amplitude level of the normal transmission output of the wireless communication device 1 until "t3" because the transmission signal of the wireless communication device 1 is amplitude-limited and transmitted via the amplitude limiting circuit 24. In "A" of FIG. 5, the dashed line shows a case where the amplitude limiting function of the amplitude limiting circuit 24 does not perform amplitude limiting. Therefore, it is possible to reduce the amplitude level immediately before the switching circuit 22 is released at the timing of "t3".

[0035] The path switching signal is also transmitted to the amplification control circuit 25. The amplification control circuit 25 outputs an amplification control signal to the amplification circuit 20 to set the amplification degree (gain) of the amplification circuit 20. As shown in FIG. 5, the amplification control circuit 25 increases the gain of the amplification circuit 20 over a predetermined time from a predetermined time when the path switching signal transitions to timing "t1". The initial value of the gain set by the amplification control circuit 25 to the amplification circuit 20 and characteristics such as the slope and curve of the gain versus time are design matters. However, at timing "t4" when the switching circuit 22 is in a transmitting state, the gain set by the amplification control circuit 25 to the amplification circuit 2 is in the process of increasing, and the gain needs to be maximized after a predetermined time has passed since "t4". It is desirable that the gain set by the amplification control circuit 25 to the amplification circuit 2 starts to increase from the minimum gain state within the period T2.

[0036] On the other hand, as shown in FIG. 5, at time "t3", the switching circuit 22 goes into the released state, so that the amplitude limitation by the amplitude limiting circuit 24 is no longer performed, and the "wireless communication device transmission output" returns to the amplitude level at the start of original transmission by the wireless communication device 1, and increases toward the transmission output that was set for the wireless communication device 1.

[0037] The amplitude level of the "amplifier-transmission signal" immediately after "t4" is the amplitude level of the transmission output of the wireless communication device 1 at "t4" amplified by the amplifier circuit 20 based on the gain setting set by the amplifier control circuit 25. The amplifier control circuit 25 sets an appropriate gain in the amplifier circuit 20 so that the amplitude level of the transmission signal immediately after "t4" is equal to or lower than the amplitude level of the transmission signal immediately before "t3".

[0038] As explained above, unwanted radiation can be suppressed by lowering the transmission output before and after the momentary interruption, that is, the amplitude level of the transmission output just before "t3" and the amplitude level of the transmission output just after "t4". The amplifier device 2 of embodiment 1 of the present invention limits the amplitude level of the transmission output just before "t3" by the amplitude limiting function (amplitude limiting circuit 24) of the amplitude limiting circuit 24, and limits the amplitude level of the transmission output just after "t4" by the amplification control signal of the amplification control circuit 25, thereby reducing the transmission output before and after the momentary interruption associated with switching between transmission and reception in the carrier control system, and suppressing unwanted radiation.

[0039] (Embodiment 2) Generally, it is considered desirable to transmit wireless communication with the minimum transmission power required for that communication. Therefore, there are cases where it is not necessary to increase the transmission power of the amplifier 2 while keeping the configuration of the wireless communication equipment 100 unchanged. Specifically, when it is not necessary to increase the transmission power of the amplifier 2, it is necessary for the amplifier 2 to stop the switching operation by the carrier control and to divert the transmission signal from the wireless communication device 1 and supply it to the antenna 3. However, in the first embodiment of the present invention, since the diversion path has an amplitude limiting function, the transmission signal of the wireless communication device 1 cannot be output from the antenna 3 even if the switching operation by the carrier control is stopped while the amplifier 2 is connected.

[0040] The configuration of an amplifying device 2A according to embodiment 2 of the present invention is shown in Fig. 6. The amplifying device 2A according to embodiment 2 includes a second switching circuit 32 (321, 322), a bypass circuit 31, a filter circuit 30, and a second switching control circuit 33 in addition to the configuration of embodiment 1. The switching circuit in the first embodiment is the first switching circuit 22 (221, 222) in the second embodiment, and the switching control circuit 23 in the first embodiment is the first switching circuit 23 in the second embodiment.

[0041] The second switching control circuit 33 switches the second switching circuit 32 between selecting a path (detour path) connecting the wireless communication device 1 and the antenna 3 via the detour circuit 31, and selecting a path (amplification path) connecting the wireless communication device 1 and the antenna 3 via either the amplifier circuit 20 or the amplitude limiting circuit 24. When selecting the detour path, the second switching control circuit 33 may stop supplying power to the amplifier circuit 20, the first switching circuit 22, the first switching control circuit 23, and the amplification control circuit 25. When selecting the detour path, the second switching control circuit 33 outputs a detour selection signal, and when selecting the amplification path, it outputs an amplification selection signal.

[0042] In the second switching circuit 32, the second switching circuit 321 is disposed on the input side (connector C1 side) and the second switching circuit 322 is disposed on the output side (connector C2 side). The second switching circuit 32 switches the path connecting the wireless communication device 1 and the antenna 3 according to a bypass selection signal or an amplification selection signal output from the second switching control circuit 33.

[0043] The detouring circuit 31 is a circuit that becomes a path that connects the wireless communication device 1 and the antenna 3 when the second switching control circuit 33 outputs a detouring selection signal and the second switching circuit 32 selects the detouring path. The detouring circuit 31 does not require any particular circuit components, but since a high-frequency transmission signal or reception signal passes through it, it is necessary for the detouring circuit 31 to be a path with little transmission loss. The detouring circuit 31 may use components such as a coaxial cable as necessary.

[0044] The filter circuit 30 suppresses harmonics generated by the amplifier circuit 20. The filter circuit 30 is, for example, a low-pass filter, and its characteristics are set such that the cutoff frequency is set to suppress harmonics in a frequency band that the amplifier circuit 20 can amplify. The filter circuit 30 is disposed on the output side of the amplifier circuit 20 in the amplification path. In detail, the filter circuit 30 is disposed between the switching circuit 222 and the switching circuit 322. That is, the filter circuit 30 is not interposed in the path of the second detour circuit. Therefore, the detour path can transmit signals in a frequency band other than the frequency band that the amplifier circuit 20 can amplify. For example, when the transmission frequency of the wireless communication device 1 has a frequency band other than the frequency band that the amplifier circuit 20 can amplify, and when the transmission frequency of the wireless communication device 1 communicates in a frequency band other than the frequency band that the amplifier circuit 20 can amplify, the amplifier device 20A can communicate via the second detour circuit. When the wireless communication device 1 cannot communicate in a frequency band other than the frequency band that can be amplified by the amplifier circuit 20, the filter circuit 30 may be disposed between the second switching circuit 322 and the connector C2.

[0045] The filter circuit 30 also suppresses harmonics generated by the amplitude limiting circuit 24 limiting the amplitude. The amplitude limiting circuit 24 distorts the passing signal to limit the original amplitude so that it does not exceed a certain amplitude level. This distortion occurs over a wide band and therefore includes harmonic components. The period between "t2" and "t3" shown in FIG. 4 of the first embodiment is a period during which the amplitude level of the transmission signal from the wireless communication device 1 is suppressed by the amplitude limiting circuit 24. During this period, a wideband signal that should not be output is generated, although the amplitude level is limited. Therefore, the filter circuit 30 is disposed between the switching circuit 222 and the switching circuit 322 so as not to supply a part of the wideband signal generated by the amplitude limiting circuit 24 to the antenna.

[0046] The amplifier 2A according to the second embodiment of the present invention may include an operation unit that receives an operation to select whether to use a bypass circuit or an amplifier circuit, although the configuration of the operation unit operated by an employee of the wireless communication equipment 100 is not shown. When the power switch of the amplifier 2A is off, that is, in the initial state, the bypass circuit is selected. When the power switch of the amplifier 2A in the second embodiment is on and the bypass circuit is selected, an input signal is not transmitted to the first switching control circuit, so that switching between transmission and reception by the carrier control method does not occur. However, since there is no point in supplying power to circuits such as the amplifier circuit 20, the amplifier control circuit 25, and the first switching control circuit 23, the second control circuit may stop supplying power to these circuits when the bypass circuit is selected.

[0047] With the above-described configuration, the amplifying device 2A according to the second embodiment of the present invention has the following features: (1) When the amplification path is selected, as in the first embodiment, the transmission output before and after the momentary interruption caused by switching between transmission and reception in the carrier control system can be reduced, and unnecessary radiation can be suppressed. (2) When the bypass path is selected, the power supply to the amplifier circuit 20, the first switching circuit 22, the switching control circuit 23, and the amplifier control circuit 25 is stopped, so that the power consumption of the amplifier device 2 can be reduced. (3) When the wireless communication device 1 is capable of transmitting and receiving signals in frequency bands other than the frequency bands that the amplifier device 2 can transmit, the wireless communication device 1 can be connected to the antenna 3 without passing signals in frequency bands other than the frequency bands that the amplifier device 2 can transmit through the filter circuit 30.

[0048] (Embodiment 3) The configuration of an amplifier 2B according to a third embodiment of the present invention is shown in Fig. 7. The amplifier 2B according to the third embodiment of the present invention is characterized in that it essentially serves as a detour path by stopping the amplitude limiting function of the amplitude limiting circuit 24 in the first embodiment. The detour path connects the wireless communication device 1 and the antenna 3 without passing through the amplifier circuit 20 when the transmission output of the wireless communication device 1 is not increased by the amplifier 20.

[0049] The amplifying device 2 according to the third embodiment of the present invention includes a filter circuit 40 and a control circuit 43 in addition to the configuration of the first embodiment. The amplitude limiting circuit 44 in the third embodiment is different from the amplitude limiting circuit 24 in the first embodiment. The control circuit 43 controls to stop or activate the amplitude limiting function of the amplitude limiting circuit 44. The filter circuit 40 is a low-pass filter that mainly suppresses the frequency band of harmonics of the amplifier circuit 20, similar to the second embodiment.

[0050] The details of the amplitude limiting circuit 41 of the amplifier device 2 according to the third embodiment of the present invention will be described with reference to FIG. 8. The amplitude limiting circuit 44 shown in FIG. 8 includes a transmission circuit 441, a switch 442, and an amplitude limiting element 443. The transmission circuit 441 is connected to the switching circuit 221 and the switching circuit 222, and is a path for transmitting a transmission signal (input signal) output from the wireless communication device 1 to the antenna 3. The switch 442 is a switch that connects or disconnects the amplitude limiting element 443 to the transmission circuit 441 according to a control signal output from the control circuit 43. That is, the switch 442 is an amplitude limiting release circuit that releases the amplitude limit of the amplitude limiting circuit 44. The amplitude limiting element 443, in a state connected to the transmission circuit 441 via the switch 442, limits the amplitude of the signal transmitted to the transmission circuit 441 to a predetermined amplitude level. Moreover, when the switch 442 is released, the connection to the transmission circuit 441 is released, and therefore the amplitude limiting element 443 does not limit the amplitude of the signal transmitted to the transmission circuit 441.

[0051] The control circuit 43 of the amplifier 2 according to the third embodiment of the present invention outputs a signal to control the switch 442 in the amplitude limiting circuit 44. When the wireless communication device 1 performs communication via the amplifier 2 and performs amplification by the amplifier 2, the control circuit 43 performs control to turn on the switch 442, thereby activating the amplitude limiting function of the amplitude limiting circuit 44. As described above, the amplifier 2 according to the third embodiment of the present invention uses the amplitude limiting function to suppress unwanted radiation that occurs when a momentary interruption in the transmission signal occurs when switching between transmission and reception using the carrier control system.

[0052] Furthermore, when the wireless communication device 1 communicates via the amplifier device 2 without amplification by the amplifier device 2, the control circuit 43 controls to turn off the switch 442 and stops the operation of the amplitude limiting function of the amplitude limiting circuit 44. By the control circuit 43 turning off the amplitude limiting function of the amplitude limiting circuit 44, the amplitude limiting circuit 44 essentially becomes a detour path within the amplifier device 2.

[0053] 9 shows a modified example of the amplitude limiting circuit 44 of the amplifier device 2 according to the third embodiment of the present invention. Whereas the switch 442 in the third embodiment only opens and closes, in the modified example a bidirectional contact is used to switch between the path of the transmission path 441 and the path of the amplitude limiting element 443. In the amplitude limiting circuit 44 of the third embodiment, the switch 442 and the amplitude limiting element 443 are connected to the transmission path 441, so that the length of the pattern for connection to the switch 442 and the electrical length inside the switch 442 may affect the frequency of the signal transmitted via the transmission path 441. On the other hand, since the configuration of the modified example is not affected by the length of the pattern for connection to the switch 442, the modified example is preferable when the frequency at which communication is performed by the wireless communication equipment 100 is relatively high, for example, 1 GHz or higher.

[0054] In the amplifier device 2A in the second embodiment of the present invention, when the power switch is on and the bypass circuit is selected, the input signal is not transmitted to the first switching control circuit, so that switching between transmission and reception by the carrier control method does not occur. However, in the third embodiment, even if the amplitude limiting function of the amplitude limiting circuit 44 is released and the circuit is essentially a bypass circuit, the input signal is input to the switching control circuit 23, so switching between transmission and reception by the carrier control method occurs. Therefore, the control circuit of the amplifier circuit 2B in the third embodiment releases the amplitude limiting function of the amplitude limiting circuit 44 and controls to at least stop the carrier detection operation of the switching control circuit 23. In addition, since there is no point in supplying power to circuits such as the amplifier circuit 20 and the amplifier control circuit 25, the control circuit may stop supplying power to these circuits when the amplitude limiting function of the amplitude limiting circuit 44 is released.

[0055] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the gist of the present invention. [Explanation of symbols]

[0056] 1. Wireless communication devices 2 Amplification equipment 3 Antennas 100 Wireless communication equipment 20 Amplification circuit 21 Detour circuit 22 Switching circuit (first switching circuit) 23 Switching control circuit (first switching control circuit) 24 Amplitude limiting circuit, 241 Transmission path, 243 Amplitude limiting element 25 Amplification control circuit 30 Filter Circuit 32 Second switching circuit 33 Second switching control circuit 43 Control circuit 44 Amplitude limiting circuit, 441 Transmission circuit, 442 Switch, 443 Amplitude limiting element

Claims

1. an amplifier circuit for amplifying an input signal; an amplitude limiting circuit for limiting the amplitude of the input signal; Switching between a path via the amplifier circuit and a path via the amplitude limiting circuit With the circuit, When the input signal is detected, the switching circuit is A control is performed to switch a connection from a path via an amplitude limiting circuit to a path via the amplifier circuit. A switching control circuit for an amplification control circuit for controlling the amplification degree of the amplifier circuit; The switching circuit switches the connection between the path of the amplitude limiting circuit and the path of the amplifier circuit. In this case, during a non-connection period in which no connection is made to any of the routes, The amplification control circuit controls the amplifier circuit to setting the amplifier circuit to start amplifying from a first predetermined time within the non-connection period; Furthermore, the amplification degree of the amplifier circuit is controlled to increase over time. Amplification device.

2. a bypass circuit that outputs the input signal without passing through the amplifier circuit or the amplitude limiting circuit; A path via the bypass circuit and a path via the amplifier circuit or the amplitude limiting circuit. A second switching circuit for switching the connection; A switching circuit on the output side of the amplifier circuit or the amplitude limiting circuit, and a third switching circuit on the output side of the bypass circuit A filter that suppresses frequencies corresponding to harmonics of the input signal is provided on the path between the switching circuit and the input signal. The second switching circuit is connected to a path via the bypass circuit and to the amplifier circuit or the amplitude control circuit. a second switching control circuit that controls connection to either one of the paths via the limiting circuit and the path via the Equipped with The second switching control circuit controls a connection to a path via the bypass circuit, and controls the switching control circuit to stop the operation of detecting the input signal.

2. The amplifier circuit according to claim 1.

3. the amplitude limiting circuit includes an amplitude limit release circuit that releases the limit on the amplitude; outputting an amplitude limit release signal for causing the amplitude limit release circuit to release the amplitude limit; A control circuit is provided to stop the operation of detecting the input signal in the switching control circuit. R, 2. The amplifier device according to claim 1.

4. The amplitude limiting circuit includes: a transmission circuit for transmitting a signal within the amplitude limiting circuit; an amplitude limiting element that limits the amplitude of a signal transmitted to the transmission circuit; Equipped with The amplitude limiting release circuit releases the connection between the transmission circuit and the amplitude limiting element. release the amplitude limit, 4. An amplifier device according to claim 3.

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