JP7458225B2 - Transmitting device and transmitting method - Google Patents

Description

The present invention relates to a transmitting device and a transmitting method.

In a transmitting device that transmits a radio signal that is a high-frequency signal, a configuration is disclosed in which an isolator or circulator (hereinafter sometimes referred to as an isolator or the like) is provided at the output stage of an amplifier. When a high frequency impedance mismatch occurs between a transmitting device and an external load connected to its output side, such as an antenna, a reflected signal is returned from the external load to the amplifier side. Isolators and the like have a function of blocking reflected signals from reaching the amplifier, thereby preventing deterioration of the amplifier and reduction in performance (efficiency, gain, output power, etc.) (see Patent Document 1).

Patent No. 6036847

However, since isolators and the like are generally large and expensive, it is preferable to remove them from the configuration in order to reduce size and cost. By matching the impedance between the transmitting device and the external load (for example, matching the characteristic impedance to 50 Ω), it is possible to prevent the occurrence of reflected signals, making it possible to omit isolators and the like.

However, if the external load is a load whose impedance can vary, it is difficult to match the impedance. Note that an antenna is an example of a load whose impedance can vary. The impedance of an antenna can vary depending on the environment such as the weather. Even with other loads, the impedance may vary depending on changes in the surrounding environment.

The present invention has been made in view of the above, and an object of the present invention is to provide a transmitting device and a transmitting method that are suitable for downsizing and cost reduction, and that can reduce the influence of reflected signals from a load.

In order to solve the above problems and achieve the objects, one aspect of the present invention provides a transmitter including an amplifier that amplifies an input signal to generate an amplified signal and outputs the amplified signal to a load whose impedance can vary. The device includes: a distribution section that is provided in a signal path between the amplifier and the load and extracts a part of the reflected signal from the load as a distribution signal; The transmission device includes a cancellation signal generation section that generates a cancellation signal that cancels the reflected signal, and an input section that inputs the input signal and the cancellation signal to the amplifier.

The cancellation signal travels in the opposite direction to the reflected signal at a predetermined position on the signal path between the amplifier and the load, based on the reflected signal acquired by the cancellation signal generation section, and is transmitted in the opposite direction to the reflected signal. It may be configured to cancel the signal at the position.

The cancellation signal generation section may generate the cancellation signal so that it has the same amplitude and opposite phase as the reflected signal at the position.

The cancellation signal generator includes a detection unit that detects the power of the reflected signal in a signal path between the position and the load, and the cancellation signal generation unit detects the cancellation signal having an amplitude according to the power detected by the detection unit. It may also be one that generates a signal.

The detection section detects a phase difference between the reflected signal and the amplified signal in a signal path between the position and the load, and the cancellation signal generation section detects the phase difference detected by the detection section. The cancellation signal may be generated to have a phase corresponding to the cancellation signal.

The cancellation signal generation section may generate a digital cancellation signal that reflects the power information detected by the detection section, and convert the generated digital cancellation signal into analog to generate the cancellation signal. good.

The cancellation signal generation unit may generate the digital cancellation signal that reflects information about the detected phase difference.

The cancellation signal generation unit may superimpose the generated digital cancellation signal and the digital input signal and perform analog conversion processing to generate the input signal and the cancellation signal.

The system may include a power control unit that controls the power of the distribution signal extracted by the distribution unit, and a delay unit that is provided in a signal path between the position and the distribution unit and that delays the arrival time of the reflected signal at the position, and the input unit may input the distribution signal, the power of which is controlled by the power control unit, to the amplifier unit together with the input signal as the cancellation signal.

The filter may be provided in a signal path between the distribution section and the input section, and may include a filter that allows the distribution signal to pass through and attenuates electrical signals having a frequency that is at least twice as high as the distribution signal.

The transmitting device may include a temperature detection section that detects the temperature of the amplifier, and a control section that controls the power control section based on the detected temperature.

Power is controlled by a power control unit that controls the power of the distribution signal taken out by the distribution unit, a delay unit that temporally delays the distribution signal taken out by the distribution unit, and the power control unit. Additionally, it may include an input section that inputs the distribution signal temporally delayed by the delay section to the amplifier together with the input signal as the cancellation signal.

One aspect of the present invention includes an amplification step in which an amplifier amplifies an input signal to generate an amplified signal and outputs the amplified signal to a load whose impedance can vary, and a signal path between the amplifier and the load. an extraction step in which a distribution unit provided in the load extracts a part of the reflected signal from the load as a distribution signal; and a cancellation signal generation unit extracts the reflected signal based on the reflected signal extracted by the distribution unit. This is a transmission method comprising: a cancellation signal generation step of generating a cancellation signal that cancels the input signal; and an input step of inputting the input signal and the cancellation signal to the amplifier.

The transmitting device and transmitting method according to the present invention are suitable for miniaturization and low cost, and have the advantage of being able to reduce the effects of reflected signals from the load.

FIG. 1 is a diagram showing the configuration of a transmitting device according to the first embodiment. FIG. 2 is a diagram showing the configuration of a transmitting device according to the second embodiment. FIG. 3 is a diagram showing the configuration of a transmitting device according to the third embodiment. FIG. 4 is a diagram showing the configuration of a transmitting device according to the fourth embodiment. FIG. 5 is a diagram showing a configuration of a transmitting device according to the fifth embodiment. FIG. 6 is a diagram showing the configuration of a transmitting device according to Embodiment 6. FIG. 7 is a diagram showing a configuration for which the simulation calculations were performed. FIG. 8 is a diagram showing simulation calculation.

Below, an embodiment of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiment described below. Furthermore, in the description of the drawings, the same parts are appropriately given the same reference numerals. Furthermore, the drawings are schematic, and the dimensional relationships and ratios of each element may differ from reality. Furthermore, the drawings may include parts with different dimensional relationships and ratios.

(Embodiment 1)
FIG. 1 is a diagram showing the configuration of a transmitting device according to the first embodiment. Transmitting device 100 outputs a high frequency signal to antenna A. Antenna A transmits a high frequency signal as a wireless signal.

The transmitting device 100 includes an amplifier 1, a distributor 2, a digital processing unit 3, a DAC 4 which is a digital-to-analog converter, a detection unit 5, and an ADC 6 which is an analog-to-digital converter. The distributor 2, the digital processing unit 3, the DAC 4, the detection unit 5, and the ADC 6 constitute a cancellation signal generation unit 7. The cancellation signal generation unit 7 is a part that executes the cancellation signal generation step.

The amplifier 1 includes, for example, a transistor, amplifies an input signal that is a high frequency signal to generate an amplified signal S1, and outputs the amplified signal S1 to the antenna A. Antenna A is an example of a load whose impedance can vary, and reflects a part of the amplified signal S1 toward the amplifier 1 as a reflected signal S2 according to the impedance variation.

The distributor 2 is a distributor provided on the signal path between the amplifier 1 and the antenna A closer to the antenna A than the position P1. Although the position P1 can be set at any position on the signal path between the amplifier 1 and the distributor 2, it is preferable that the position P1 be closer to the amplifier 1 than the distributor 2. Distributor 2 has at least terminals 2a, 2b, and 2c. The distributor 2 passes the amplified signal S1 input from the amplifier 1 to the terminal 2a, and outputs it to the antenna A from the terminal 2b. Further, the distributor 2 passes the reflected signal S2 input from the antenna A to the terminal 2b, and outputs it to the amplifier 1 from the terminal 2a. Moreover, when the distributor 2 passes the reflected signal S2, it extracts a part of the reflected signal S2 as a distribution signal and outputs it from the terminal 2c. The distributor 2 can be configured using a directional coupler, for example. In this case, the unused terminals of the directional coupler are connected to the ground via a resistor having an impedance of 50Ω, for example, and subjected to anti-reflection treatment.

The detection unit 5 includes, for example, a diode, and receives the input of the distribution signal output from the terminal 2c. Thereby, the detection unit 5 detects the amplitude of the reflected signal S2 in the signal path between the position P1 and the antenna A, and uses this to detect the power of the reflected signal S2. The detection unit 5 outputs an electrical signal including information on the detected power to the ADC 6. The ADC 6 converts a current signal, which is an analog signal, into a digital signal (for example, a voltage signal) and outputs the digital signal to the digital processing section 3.

The digital processing section 3 performs digital processing of high frequency signals. The digital processing unit 3 includes processors such as a CPU (Central Processing Unit), ASIC (Application Specific Integrated Circuit), FPGA (Field-Programmable Gate Array), and DSP (Digital Signal Processor), RAM (Random Access Memory), and ROM ( It can be constructed using a semiconductor memory that stores programs and data, such as a read-only memory (Read Only Memory) or an Erasable Programmable Read Only Memory (EPROM).

The digital processing section 3 includes a signal input section 3a, a distribution section 3b, a delay section 3c, an amplitude control section 3d, a subtraction section 3e, as functional sections realized by cooperation of hardware and software. It also includes a control section 3f.

The signal input section 3a receives input of a digital signal and outputs it to the distribution section 3b. The distribution section 3b distributes the digital signal to the delay section 3c and the subtraction section 3e. The delay section 3c temporally delays the input digital signal and outputs it to the amplitude control section 3d. The amplitude control section 3d controls the amplitude (eg, voltage value) of the input digital signal and outputs it to the subtraction section 3e. The control section 3f controls the amplitude control section 3d based on the digital signal input from the ADC 6. As a result, the digital signal whose amplitude is controlled by the amplitude control section 3d is a digital signal in which information about the power of the reflected signal S2 detected by the detection section 5 is reflected.

The subtraction unit 3e performs a subtraction process of inverting the sign and adding the digital signal input from the amplitude control unit 3d to the digital signal input from the distribution unit 3b. The digital signal input from the distribution section 3b is a digital input signal corresponding to the input signal to be amplified by the amplifier 1. A digital signal generated by inverting the sign of the digital signal input from the amplitude control section 3d corresponds to a digital cancellation signal. The digital cancellation signal is also a digital signal on which information about the power of the reflected signal S2 detected by the detection unit 5 is reflected.

DAC4 performs analog conversion processing on the digital signal output from subtraction unit 3e and outputs it to amplifier 1. The digital signal output from subtraction unit 3e can be said to be a digital signal in which the digital input signal and the digital cancellation signal are superimposed. Therefore, DAC4 superimposes the digital cancellation signal and the digital input signal and performs analog conversion processing to generate the input signal and the cancellation signal.

The amplifier 1 performs an amplification step of amplifying an input signal to generate and output an amplified signal, and also amplifies a cancellation signal and outputs the amplified cancellation signal. The amplified signal S1 and the amplified cancellation signal S3 travel toward antenna A along the signal path between amplifier 1 and antenna A.

The cancellation signal S3 travels along the signal path between the amplifier 1 and the antenna A in the opposite direction to the reflected signal S2, and arrives at the position P1 at the same time as the reflected signal S2 at a predetermined time. Here, if the cancellation signal S3 has a waveform like waveform W3, and the reflected signal S2 has a waveform like waveform W2, then waveform W3 has the same amplitude and opposite phase as waveform W2 at position P1. It is. As a result, the cancellation signal S3 cancels the reflected signal S2 at position P1. As a result, the reflected signal S2 is prevented from being input to the amplifier 1.

The cancellation signal S3 is generated based on the reflected signal S2. Specifically, the amplitude of the cancellation signal S3 is increased or decreased by the control section 3f controlling the amplitude control section 3d according to the power of the reflected signal S2 detected by the detection section 5, and the amplitude of the reflected signal S2 is increased or decreased. It is controlled so that it is the same as . Further, the phase of the cancellation signal S3 is set by a time delay given by the delay section 3c. The delay time given by the delay unit 3c is determined by the characteristics of the signal path between the transmitting device 100 and the antenna A and the cancellation signal generation unit 7 so that the phase of the cancellation signal S3 is opposite to that of the reflected signal S2 at the position P1. It is set in advance according to the characteristics of.

For example, the gain of the amplifier 1 is A [dB], the power ratio of the distribution signal to the reflected signal S2 in the distributor 2 is C ₁ [dB], and the power value of the distribution signal detected by the detector 5 is P _ref [dBm ], and the value corresponding to the power of the digital signal input to the amplitude control unit 3d is P _in [dBm], then the control unit 3f calculates the digital signal input to the amplitude control unit 3d by the following formula ( 1) Set the power attenuation amount ATT [dB].
ATT=P _ref -P _in -A-C ₁ ... (1)

In the transmitting device 100 configured as described above, the reflected signal S2 generated at the antenna A is suppressed from being input to the amplifier 1 by the cancellation signal S3. Further, in the transmitting device 100, the cancellation signal generation unit 7 detects the power of the reflected signal S2 and reflects it on the amplitude of the cancellation signal S3. As a result, even if the impedance of antenna A fluctuates and the power of reflected signal S2 fluctuates, input of reflected signal S2 to amplifier 1 is suppressed regardless of the fluctuation.

(Embodiment 2)
FIG. 2 is a diagram showing the configuration of a transmitting device according to the second embodiment. The transmitting device 100A has a configuration in which the transmitting device 100 according to the first embodiment is replaced with a distributor 2A for the distributor 2, a digital processing unit 3A for the digital processing unit 3, and a detection unit 5A for the detection unit 5. . The distributor 2A, the digital processing section 3A, the DAC 4, the detection section 5A, and the ADC 6 constitute a cancellation signal generation section 7A. In the following description, descriptions of common configurations between the transmitting device 100 and the transmitting device 100A will be omitted as appropriate.

Distributor 2A has terminals 2a, 2b, 2c, and 2d. The distributor 2A passes the amplified signal S1 input from the amplifier 1 to the terminal 2a, and outputs it to the antenna A from the terminal 2b. Further, the distributor 2A passes the reflected signal S2 input from the antenna A to the terminal 2b, and outputs it to the amplifier 1 from the terminal 2a. Moreover, when the distributor 2A passes the reflected signal S2, it extracts a part of the reflected signal S2 as a first distributed signal, which is a distributed signal, and outputs it from the terminal 2c. Moreover, when the distributor 2A passes the amplified signal S1, it extracts a part of the amplified signal S1 as a second distribution signal, which is a distribution signal, and outputs it from the terminal 2d. The distributor 2A can be configured using a directional coupler, for example.

The detector 5A receives the first and second distribution signals output from the terminals 2c and 2d. As a result, the detector 5 detects the power of the reflected signal S2 in the signal path between the position P1 and the antenna A and the phase difference between the amplified signal S1 and the reflected signal S2. The detector 5A outputs an electrical signal including information on the detected power and phase difference to the ADC 6. The ADC 6 converts the current signal, which is an analog signal, into a digital signal and outputs it to the digital processing unit 3A.

The digital processing section 3A has a configuration in which the delay section 3c in the digital processing section 3 is replaced with a delay control section 3Ac, and the control section 3f is replaced with a control section 3Af. Like the digital processing section 3, the digital processing section 3A can be configured using a processor and a semiconductor memory.

In addition to the functions of the digital processing section 3, the digital processing section 3A is configured such that a delay control section 3Ac can control the amount of time delay of the input digital signal. The amount of delay is determined by the control section 3Af controlling the delay control section 3Ac in accordance with the phase difference detected by the detection section 5A. As a result, the cancellation signal generation unit 7A generates a digital cancellation signal in which information about the detected phase difference is reflected, and based on this, a cancellation signal having a phase corresponding to the detected phase difference is generated. Generate S3.

As a result, the cancellation signal S3 is controlled so that the amplitude is the same as the amplitude of the reflected signal S2 by the amplitude control section 3d according to the power of the reflected signal S2 detected by the detection section 5A, and the phase is more accurately controlled by the delay control unit 3Ac in accordance with the phase of the reflected signal S2 detected by the detection unit 5A so that the phase is opposite to that of the reflected signal S2. The phase of the cancellation signal S3 is set by the time delay provided by the delay section 3c.

In the transmitter 100A configured as above, even if the impedance of the antenna A fluctuates and the power of the reflected signal S2 fluctuates, the reflected signal S2 is sent to the amplifier 1 regardless of the fluctuation. Input is suppressed. Furthermore, even if the delay time is initialized in advance in the delay control unit 3Ac, even if the delay time to be given changes from the initial setting, the delay control unit 3Ac controls the delay time to increase or decrease, and the cancellation signal S3 It is possible to more reliably realize a state in which the phase is opposite to that of the reflected signal S2 at the position P1.

(Embodiment 3)
FIG. 3 is a diagram showing the configuration of a transmitting device according to the third embodiment. The transmitting device 100B includes an amplifier 1, a distributor 2, an input section 8, a power combiner 9, a delay section 10, a loop section 11, and a power control section 12. The distributor 2, the loop section 11, and the power control section 12 constitute a cancellation signal generation section 7B. In the following description, descriptions of common configurations between transmitting device 100 and transmitting device 100B will be omitted as appropriate.

The input unit 8 receives an input signal, which is a high-frequency signal, and outputs it to the power combiner 9. The power combiner 9 has terminals 9a, 9b, and 9c, and outputs the input signal input to terminal 9a from terminal 9c to the amplifier 1.

Amplifier 1 amplifies an input signal to generate an amplified signal S1, and outputs the amplified signal S1 to antenna A. Antenna A reflects a part of the amplified signal S1 toward the amplifier 1 as a reflected signal S2.

The distributor 2 passes the amplified signal S1 input from the amplifier 1 to terminal 2a and outputs it from terminal 2b to the antenna A. The distributor 2 also passes the reflected signal S2 input from the antenna A to terminal 2b and outputs it from terminal 2a to the amplifier 1. When the distributor 2 passes the reflected signal S2, it also extracts a portion of the reflected signal S2 as a distribution signal and outputs it from terminal 2c.

The loop section 11 is a signal path between the terminal 2c of the distributor 2 and the terminal 9b of the power combiner 9. The power control section 12 is provided in the middle of the loop section 11 and controls the power of the input high frequency signal. For example, the power control unit 12 attenuates the power of the input high-frequency signal by a predetermined amount and outputs the attenuated power.

The distribution signal travels through the loop section 11 from the distributor 2 to the power combiner 9. The distribution signal may also be called a feedback signal. The power control unit 12 attenuates the power of the distribution signal and outputs it to the power combiner 9. Power combiner 9 outputs the distribution signal input to terminal 9b to amplifier 1 from terminal 9c. That is, the power combiner 9 combines the power of the input signal and the distribution signal and outputs the combined power. The power combiner 9 is an example of an input unit that inputs a power-controlled distribution signal to the amplifier 1.

The amplifier 1 amplifies the power-controlled distribution signal and outputs it as a cancellation signal S4. The cancellation signal S4 travels towards antenna A along the signal path between amplifier 1 and antenna A.

The cancellation signal S4 travels along the signal path between the amplifier 1 and the antenna A in the opposite direction to the reflected signal S2, and arrives at the position P1 at the same time as the reflected signal S2. Note that the reflected signal S2 reaches the position P1 after traveling through the delay unit 10 as a signal path. The delay unit 10 is, for example, a transmission line whose electrical length is set so that the time from when the reflected signal S2 is input to the delay unit 10 to when it is output is a predetermined time (delay time). Thereby, the delay unit 10 delays the arrival time of the reflected signal S2 to the position P1.

Here, if the cancellation signal S4 has a waveform like waveform W4, and the reflected signal S2 has a waveform like waveform W2, then waveform W4 has the same amplitude and opposite phase as waveform W2 at position P1. It is. As a result, the cancellation signal S4 cancels the reflected signal S2 at position P1. As a result, the reflected signal S2 is prevented from being input to the amplifier 1.

The cancellation signal S4 is a signal generated by passing the distribution signal, which is a part of the reflected signal S2, through the loop section 11, the power control section 12, the power combiner 9, and the amplifier 1. The power of the cancellation signal S4 is controlled according to the power of the reflected signal S2 detected by the detection unit 5 so as to have the same amplitude as the reflected signal S2. Further, the relationship between the phase of the reflected signal S2 and the phase of the cancellation signal S4 at the position P1 is set by the time delay provided by the loop section 11 and the delay section 10. The time delay provided by the loop section 11 and the delay section 10 is set in advance so that the phase of the cancellation signal S4 is in opposite phase to the reflected signal S2 at the position P1.

For example, if the gain of the amplifier 1 is A [dB], the power ratio of the distributed signal to the reflected signal S2 in the divider 2 is C ₁ [dB], and the power loss in the power combiner 9 is C ₂ [dB], then The power control unit 12 is set to a power attenuation amount ATT [dB] expressed by the following formula (2).
ATT=-A-C ₁ -C ₂ ... (2)

Further, for example, the phase corresponding to the delay time given by the delay unit 10 is expressed as φ _delay [degree], and the phase at the time when the reflected signal S2 is input to the delay unit 10 as seen from the terminal 2a is expressed as φ ₀ [degree]. If the phase corresponding to the delay time given by the loop unit 11 etc. until the distribution signal reaches the position P1 as the cancellation signal S4 is expressed as φ _FB [degree], then the following equation (3) holds true. It is preferable.
φ _delay =-φ ₀ +φ _FB ±180... (3)

In the transmitting device 100B configured as described above, the reflected signal S2 generated at the antenna A is suppressed from being input to the amplifier 1 by the cancellation signal S4. Further, the transmitting device 100C can be configured only with analog circuits.

(Embodiment 4)
FIG. 4 is a diagram showing the configuration of a transmitting device according to the fourth embodiment. The transmitting device 100C has a configuration in which a filter 13 is added to the transmitting device 100B according to the third embodiment. The distributor 2, the loop section 11, and the power control section 12 constitute a cancellation signal generation section 7C.

The filter 13 is provided in the signal path between the distributor 2 and the power combiner 9, and in this embodiment, it is provided closer to the distributor 2 than the power control section 12 in the loop section 11; Not limited. That is, the filter 13 may be provided closer to the power combiner 9 than the power control section 12.

The filter 13 is a filter that allows the distribution signal to pass through and attenuates electrical signals having a frequency that is at least twice that of the distribution signal.

In the transmitting device 100C configured as described above, the cancellation signal S4 prevents the reflected signal S2 generated at antenna A from being input to the amplifier 1. Furthermore, in the transmitting device 100C, when higher-order components such as double waves are generated at the transmitting device 100C or antenna A, the phase relationship is not such that the reflected signal is cancelled out by the cancellation signal for all higher-order components. However, because the filter 13 attenuates electrical signals with frequencies more than twice that of the distribution signal, the higher-order components are prevented from oscillating due to the feedback circuit configured to include the loop section 11.

(Embodiment 5)
FIG. 5 is a diagram showing the configuration of a transmitting device according to the fifth embodiment. The transmitting device 100D has a configuration in which the power control unit 12 is replaced with a variable power control unit 12D in the transmitting device 100B according to the third embodiment, and a control unit 14 and a temperature detection unit 16 are added. The distributor 2, the loop section 11, the variable power control section 12D, the control section 14, and the temperature detection section 16 constitute a cancellation signal generation section 7D.

The variable power control unit 12D attenuates the power of the distribution signal output from the distributor 2 and outputs it to the power combiner 9. The temperature detection section 16 includes, for example, a thermistor, detects the temperature of the amplifier 1, and outputs an electric signal containing temperature information to the control section 14.

The control unit 14 controls the amount of attenuation of the power of the distribution signal in the variable power control unit 12D based on the electrical signal input from the temperature detection unit 16. The control unit 14 can be configured using an ADC, a DAC, a processor, and a semiconductor memory. The ADC performs AD conversion on the electrical signal input from the temperature detection section 16. The DAC performs DA conversion on an instruction signal for the variable power control section 12D obtained as a calculation result of the control section 14, and outputs it to the variable power control section 12D.

Here, when the temperature of the amplifier 1 changes, the gain also changes. Therefore, in the transmitting device 100D, the amount of attenuation of the power of the distribution signal in the variable power control section 12D is controlled based on the detected temperature of the amplifier 1, so that the reflected signal S2 is adjusted according to the temperature of the amplifier 1. A cancellation signal S4 of power suitable for cancellation can be generated.

For example, assuming that the gain of the amplifier 1 is A(T) [dB] which is a function of temperature T, and similar to equation (2), the variable power control unit 12D calculates the power attenuation amount ATT(T ) [dB]. Therefore, the power attenuation amount ATT(T) is controlled according to the fluctuation of A(T).
ATT(T)=-A(T)-C ₁ -C ₂ ... (4)

In the transmitter 100D configured as described above, the reflected signal S2 generated at the antenna A is suppressed from being input to the amplifier 1 by the cancellation signal S4. Further, a suitable cancellation signal S4 can be generated in accordance with temperature fluctuations of the amplifier 1.

(Embodiment 6)
FIG. 6 is a diagram showing the configuration of a transmitting device according to Embodiment 6. The transmitting device 100E is the same as the transmitting device 100B according to the third embodiment, except that the power combiner 9, the loop section 11, and the power control section 12 are deleted, and the detecting section 5, the variable power control section 12E, the delay section 13E, and the control section 14E are added. , a power divider 17, a power combiner 18, and a loop section 19 are added. The detection section 5, variable power control section 12E, delay section 13E, control section 14E, power divider 17, power combiner 18, and loop section 19 constitute a cancellation signal generation section 7D.

Power divider 17 includes terminals 17a, 17b, and 17c. Power combiner 18 includes terminals 18a, 18b, and 18c.

The power divider 17 outputs the input signal input from the input section 8 to the terminal 17a from the terminal 17b to the terminal 18a of the power combiner 18, and outputs a part of the input signal as a distribution signal from the terminal 17c to the delay section 13E. do.

The delay unit 13E is, for example, composed of a transmission line whose electrical length is set so that the time from when the distribution signal is input to the delay unit 13E until it is output is a predetermined delay time. In this way, the delay unit 13E delays the distribution signal in time.

The loop section 19 is a signal path between the delay section 13E and the variable power control section 12E. The variable power control section 12E controls the power of the distribution signal input from the loop section 19, attenuates it by a variable amount, and outputs it to the terminal 18c of the power combiner 18.

The power combiner 18 combines the power of the power-controlled distribution signal with the power of the input signal and outputs the combined power from terminal 18c to amplifier 1. Amplifier 1 amplifies the power-controlled distribution signal and outputs it as a cancellation signal S4.

The detection unit 5 receives the input of the distribution signal output from the terminal 2c of the distributor 2. Thereby, the detection unit 5 detects the amplitude of the reflected signal S2 in the signal path between the position P1 and the antenna A, and uses this to detect the power of the reflected signal S2. The detection unit 5 outputs an electrical signal including information on the detected power to the control unit 14E. The control section 14E can be configured with an analog circuit.

The control unit 14 controls the amount of attenuation that the variable power control unit 12E applies to the distribution signal based on the power information detected by the detection unit 5 in the input electrical signal.

In the transmitting device 100E configured as described above, the reflected signal S2 generated at the antenna A is suppressed from being input to the amplifier 1 by the cancellation signal S4. Further, since the amount of attenuation in the variable power control section 12E is controlled according to the power of the detected reflected signal S2, it is possible to generate a suitable cancellation signal S4 according to the power of the reflected signal S2.

Embodiment 6 described above has a configuration including the delay section 10 as in Embodiments 3 to 5, but as in Embodiments 1 and 2, the distribution signal whose power is controlled and the input signal are combined. can be output to the amplifier 1 from the terminal 18c. Therefore, as already shown in FIGS. 1, 2, etc., the amplifier 1 and the terminal 2a of the distributor 2 may be connected without providing the delay section 10.

(Simulation calculation)
Here, power simulation calculations were performed for a configuration in which an input signal is directly input to a load whose impedance can vary and a configuration in which a cancellation signal is generated.

FIG. 7 is a diagram showing a configuration in which simulation calculations were performed. This device 1000 includes an input section 1001, a load 1002, and an element section 1100. Element section 1100 includes a power combiner 1110, a directional coupler 1120, a resistor 1130, an amplifier 1140, and a loop section 1150.

A high frequency signal input from input section 1001 is input to power combiner 1110 from terminal 1111 and input to directional coupler 1120 from terminal 1113. Directional coupler 1120 outputs the high frequency signal input from terminal 1121 to load 1002 from terminal 1122. Load 1002 corresponds to a load whose impedance can vary, and one end is connected to ground. Further, the directional coupler 1120 allows the reflected signal input from the load 1002 to the terminal 1122 to pass to the terminal 1121. Moreover, when the distributor 2 passes the reflected signal, it extracts a part of the reflected signal as a distribution signal and outputs it to the loop section 1150 from the terminal 1123. An unused terminal 1124 of the directional coupler 1120 is connected to ground via a resistor 1130 with an impedance of 50Ω, and is subjected to anti-reflection treatment.

The loop section 1150 is a signal path provided between the terminal 1123 of the directional coupler 1120 and the terminal 1112 of the power combiner 1110, and an amplifier 1140 is provided in the middle. The distributed signal that has proceeded through the loop section 1150 and has been amplified by the amplifier 1140 is inputted from the terminal 1112 of the power combiner 1110 and outputted from the terminal 1113. That is, this device 1000 can be said to have a configuration in which the amplifier 1 and the power control section 12 of the transmitting device 100B shown in FIG. 3 are integrated as an amplifier 1140.

7 and a device (directly connected device) in which the element unit 1100 is removed from the device 1000 and the input unit 1001 and the load 1002 are directly connected, the S parameters were calculated when a high-frequency signal having a frequency of 1.8 GHz was input from the input unit 1001, and the return loss, |S11|, was obtained. The impedance _ZL of the load 1002 was changed between 5Ω and 500Ω. The characteristic parameters of each element of the device 1000 were set so as to operate optimally at a frequency of 1.8 GHz.

FIG. 8 is a diagram showing simulation calculation, and shows return loss for _ZL . Line L1 shows the characteristics of the directly connected device, and line L2 shows the characteristics of the device 1000. As shown in FIG. 8, in the direct-coupled device, return loss was extremely high at impedances other than 50Ω, but in device 1000, return loss was low over a wide range of impedances from 5 to 500Ω.

In the above embodiments, the cancellation signal has the same amplitude and opposite phase as the reflected signal, but the amplitude is not limited to being completely the same, and the phase is not limited to being completely opposite. For example, as long as the power of the reflected signal input to the amplifier is within a permissible range, the amplitudes are not limited to being completely the same, and the phases are not limited to being completely opposite.

Furthermore, the present invention is not limited to the above embodiments. The present invention also includes configurations in which the above-mentioned components are appropriately combined. For example, a filter 13 as shown in FIG. 4 may be provided to the transmitter 100D shown in FIG. Moreover, further effects and modifications can be easily derived by those skilled in the art. Accordingly, the broader aspects of the invention are not limited to the embodiments described above, but are capable of various modifications.

1 Amplifier 2, 2A Distributor 2a, 2b, 2c, 2d, 9a, 9b, 9c, 17a, 17b, 17c, 18a, 18b, 18c Terminal 3, 3A Digital processing unit 3a Signal input unit 3b Distributor 3c, 10, 13E Delay unit 3d Amplitude control unit 3e Subtraction unit 3f, 3Af, 14, 14E Control unit 3Ac Delay control unit 5, 5A Detection unit 7, 7A, 7B, 7C, 7D Cancellation signal generation unit 8 Input unit 9 Power combiner 11, 19 Loop unit 12 Power control unit 12D, 12E Variable power control unit 13 Filter 16 Temperature detection unit 17 Power distributor 18 Power combiner 100, 100A, 100B, 100C, 100D, 100E Transmitter A Antenna S1 Amplified signal S2 Reflected signal S3, S4 Cancellation signal W2, W3, W4 waveform

Claims (13)

A transmitting device comprising an amplifier that amplifies an input signal to generate an amplified signal and outputs the amplified signal to a load whose impedance can vary,
a distribution unit provided in a signal path between the amplifier and the load and extracting a part of the reflected signal from the load as a distribution signal;
a cancellation signal generation unit that generates a cancellation signal that cancels the reflected signal based on the reflected signal extracted by the distribution unit;
an input section that inputs the input signal and the cancellation signal to the amplifier;
A transmitting device comprising: The cancellation signal travels in the opposite direction to the reflected signal at a predetermined position on the signal path between the amplifier and the load, based on the reflected signal acquired by the cancellation signal generation section, and the reflected signal is transmitted in a direction opposite to the reflected signal. The transmitting device according to claim 1, wherein the transmitting device is configured to cancel the signal at the position. The transmitting device according to claim 2, wherein the cancellation signal generation unit generates the cancellation signal so that it has the same amplitude and opposite phase as the reflected signal at the position. comprising a detection unit that detects the power of the reflected signal in a signal path between the position and the load,
The transmitting device according to claim 2, wherein the cancellation signal generation section generates the cancellation signal having an amplitude according to the power detected by the detection section. The detection unit detects a phase difference between the reflected signal and the amplified signal in a signal path between the position and the load,
The transmitting device according to claim 4, wherein the cancellation signal generation section generates the cancellation signal having a phase according to the phase difference detected by the detection section. The cancellation signal generation unit generates a digital cancellation signal that reflects information on the power detected by the detection unit, and converts the generated digital cancellation signal into analog to generate the cancellation signal. 5. The transmitting device according to 4 or 5. The transmitting device according to claim 6, wherein the cancellation signal generation unit generates the digital cancellation signal on which information about the detected phase difference is reflected. The transmitting device according to claim 6 , wherein the cancellation signal generation unit superimposes the generated digital cancellation signal and the digital input signal and converts them into analog, thereby generating the input signal and the cancellation signal. a power control unit that controls power of the distribution signal taken out by the distribution unit;
a delay unit that is provided in a signal path between the position and the distribution unit and delays the arrival time of the reflected signal to the position;
Equipped with
The transmitting device according to claim 2 , wherein the input section inputs the distribution signal whose power is controlled by the power control section to the amplifier together with the input signal as the cancellation signal. The transmission according to claim 1, further comprising a filter that is provided in a signal path between the distribution section and the input section, allows the distribution signal to pass through, and attenuates an electrical signal having a frequency that is at least twice as high as the distribution signal. Device. The transmitting device according to claim 9, comprising: a temperature detection section that detects the temperature of the amplifier; and a control section that controls the power control section based on the detected temperature. a power control unit that controls power of the distribution signal taken out by the distribution unit;
a delay unit that temporally delays the distribution signal taken out by the distribution unit;
Claims 1 to 3 further comprising: an input section for controlling power by the power control section and inputting the distribution signal temporally delayed by the delay section to the amplifier together with the input signal as the cancellation signal. The transmitting device according to any one of. an amplification step in which the amplifier amplifies the input signal to generate an amplified signal and outputs the amplified signal to a load whose impedance can vary;
an extraction step in which a distribution section provided in a signal path between the amplifier and the load extracts a part of the reflected signal from the load as a distribution signal;
a cancellation signal generation step in which a cancellation signal generation unit generates a cancellation signal that cancels the reflected signal based on the reflected signal extracted by the distribution unit;
an input step of inputting the input signal and the cancellation signal to the amplifier;
Transmission method including.

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