WO2015114702A1

WO2015114702A1 - Transmission device and method for controlling same

Info

Publication number: WO2015114702A1
Application number: PCT/JP2014/005478
Authority: WO
Inventors: 憲明田和
Original assignee: 日本電気株式会社
Priority date: 2014-01-30
Filing date: 2014-10-29
Publication date: 2015-08-06
Also published as: JP6229738B2; JPWO2015114702A1

Abstract

A transmission device (1) in one embodiment contains the following: pulse-signal generators (102, 103) that convert a carrier wave (CW1) and another carrier wave (CW2) that is 90° out of phase with said carrier wave (CW1) to pulse signals (P1, P2), respectively, and output said pulse signals; delta-sigma modulators (104, 105) that output delta-sigma modulated signals (M1, M2) obtained by subjecting an in-phase component signal (I) and a quadrature component signal (Q) from a baseband signal to delta-sigma modulation synchronized on the respective pulse signals (P1, P2); a multiplier (106) that generates an RF pulse-modulated signal (R1) by multiplying one delta-sigma modulated signal (M1) by the first pulse signal (P1); a multiplier (107) that generates another RF pulse-modulated signal (R2) by multiplying the other delta-sigma modulated signal (M2) by the other pulse signal (P2); a switching-amplifier unit (20) that amplifies the RF pulse-modulated signals (R1, R2); and a combiner (15) that combines the RF pulse-modulated signals (R1, R2) amplified by said switching-amplifier unit (20).

Description

Transmitting apparatus and control method thereof

The present invention relates to a transmission device and a control method thereof.

In recent years, in wireless communications such as cellular phones and wireless LANs (Local Area Networks), OFDM (Orthogonal Frequency) with high frequency utilization efficiency and a large peak power-to-average power ratio (hereinafter referred to as PAPR). -Division (Multiplexing) is used.

In conventional wireless transmission devices, class AB amplifiers are generally used as signal amplifiers. As described above, in order to amplify a modulation signal having a large PAPR with the class AB amplifier, a sufficient back-off is required to maintain the linearity of the output signal. However, the power efficiency of the class AB amplifier is highest when the output is saturated, and decreases as the back-off increases. Therefore, there is a problem that it is difficult to amplify a modulation signal having a large PAPR with high power efficiency.

Therefore, a transmitter having a configuration in which a ΔΣ modulator and a switching amplifier are combined is attracting attention as a transmitter capable of obtaining high power efficiency. For example, the transmission device converts a multi-bit baseband signal into a 1-bit pulse waveform ΔΣ modulation signal using a ΔΣ modulator. Then, by multiplying the ΔΣ modulation signal and the carrier wave by a multiplier, an RF pulse modulation signal up-converted to the RF band is generated.

Since the amplitude of a 1-bit RF pulse modulation signal is ideally represented by only binary values, the switching amplifier can amplify the RF pulse modulation signal without generating distortion due to nonlinear characteristics. Furthermore, since the amplitude of the RF pulse modulation signal does not change even if the PAPR is large and is represented by only a binary value, the switching amplifier can amplify the RF pulse modulation signal with high power efficiency.

When a multi-bit baseband signal is converted into a 1-bit ΔΣ modulation signal using a ΔΣ modulator, quantization noise accompanying 1-bit conversion is added to the ΔΣ modulation signal. In general signal quantization, noise uniformly distributed in the frequency domain is given. However, when a delta-sigma modulator is used, the noise shaping effect based on its transfer characteristics moves the low-frequency side quantization noise to the high-frequency side, so a higher signal in the transmission signal band than general quantization. A noise-to-noise ratio can be realized. Noise components outside the signal band are removed, for example, by providing a filter in the subsequent stage. This noise shaping characteristic is determined by the order of the ΔΣ modulator and an oversampling ratio (hereinafter referred to as OSR). When the OSR is low, the noise shaping characteristics are not sufficient, and the radio characteristics required for the transmission apparatus may not be satisfied.

For example, according to Non-Patent Document 1, in order to obtain a necessary signal-to-noise ratio in the OFDM modulation scheme of IEEE 802.11a standard, a ΔΣ modulator is used at a clock frequency 32 times or 64 times the sampling frequency of the baseband signal. Need to work. Specifically, when the sampling frequency is 20 MHz, the ΔΣ modulator needs to be operated at a clock frequency of 640 MHz or 1.28 GHz. Since such a ΔΣ modulator that operates at a high-speed clock frequency in the order of GHz is difficult to realize with an FPGA, it is constructed by a digital RF circuit.

Patent Documents 1 to 4 disclose a transmission apparatus having a configuration in which a ΔΣ modulator and a switching amplifier are combined. However, in these related technologies, the clock signal supplied to the ΔΣ modulator and the carrier wave are asynchronous. Even if the reference signal source for the clock signal and the carrier wave is common, the clock signal and the carrier wave become asynchronous due to the difference in transmission path and the difference in duty ratio due to sine wave or rectangular wave.

When the clock signal and the carrier wave are asynchronous, there arises a problem that a signal having a desired pulse width cannot be obtained due to a shift in signal transition timing between the output of the ΔΣ modulator (ΔΣ modulation signal) and the carrier wave. Here, the signal transition refers to a transition of the amplitude from “H” to “L” or from “L” to “H”. When the carrier frequency is sufficiently larger than the clock frequency, the signal transition frequency of the carrier is sufficiently higher than that of the ΔΣ modulation signal, and the shift of the signal transition timing can be ignored. However, when the carrier frequency and the clock frequency are approximately the same, this influence cannot be ignored, resulting in a decrease in modulation accuracy and a decrease in power efficiency of the switching amplifier.

The radio frequency in UTRA (Universal Terrestrial Radio Access) and E-UTRA (Evolved Universal Terrestrial Radio Access) is 700 MHz to 3.5 GHz, which is similar to the clock frequency of the ΔΣ modulator. Therefore, it is necessary to prevent the above problem by synchronizing the carrier wave and the clock signal.

A solution to such a problem is disclosed in Patent Document 5. This transmission apparatus first converts a baseband signal represented by an in-phase component and a quadrature phase component into an amplitude signal and a phase signal having a constant amplitude. Next, the amplitude signal is converted into a ΔΣ modulation signal using a ΔΣ modulator, and the phase signal is converted into an RF signal using a conventional analog quadrature modulator or the like. Next, the RF signal is converted into a pulse signal using a pulse phase signal generator, and an RF pulse modulation signal is generated by multiplying the pulse signal and the ΔΣ modulation signal. At this time, the pulse signal generated by the pulse phase signal generator is supplied to the ΔΣ modulator and used as a clock signal. Thereby, since the pulse signal and the ΔΣ modulation signal can be synchronized, it is possible to prevent the signal quality from being deteriorated due to the synchronization shift.

However, in order to create such a transmission apparatus, an analog quadrature modulator or the like is required to convert the phase signal into an RF signal in addition to the ΔΣ modulator. The analog quadrature modulator is a modulator that is generally used in a transmission apparatus including a conventional class AB amplifier. That is, in order to create such a transmission device, in addition to the components necessary for the conventional transmission device, components related to ΔΣ modulation are required, which complicates the device (in other words, the circuit scale). Increased).

Furthermore, since the amplitude of the phase signal is constant, signals outside the transmission signal band cannot be suppressed by an FIR filter or the like. Therefore, the analog quadrature modulator is required to have a performance with a wider signal generation bandwidth than that for generating a normal phase amplitude modulated transmission signal. This, combined with the complexity of the device described above, increases the overall power consumption of the device.

Further, although the ΔΣ modulation signal and the pulse signal can be synchronized, the amplitude signal of the baseband signal input to the ΔΣ modulator and the pulse signal cannot be synchronized. Therefore, there is a problem that invalid data during the transition time of the amplitude signal is sampled and transmission signal distortion increases.

JP 2011-069883 A JP 2011-077741 A JP 2011-018994 A JP 2002-057332 A International Publication No. 2011/078120

As described above, in the configuration disclosed in Patent Document 5, in order to obtain the pulse signal input to the ΔΣ modulator and the mixer, the in-phase component signal I and the quadrature component signal Q of the baseband signal having a constant amplitude are obtained. A modulator (IQ modulator) that modulates the RF signal is required. For this reason, the configuration disclosed in Patent Document 5 has a problem that the circuit scale increases. Other problems and novel features will become apparent from the description of the present specification and the accompanying drawings.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a transmission apparatus and a control method thereof that can suppress an increase in circuit scale.

According to one embodiment, a transmitting apparatus includes a baseband signal generation unit that generates an in-phase component signal and a quadrature phase component signal of a baseband signal, a second carrier and a second carrier that is 90 degrees out of phase with the first carrier. First and second pulse signal generators for converting a carrier wave into first and second pulse signals having pulse waveforms, respectively, and outputting the in-phase component signal and the quadrature-phase component signal to the first and second pulses, respectively. A first and second ΔΣ modulators that perform ΔΣ modulation in synchronization with the signal and output as first and second ΔΣ modulation signals, and multiply the first ΔΣ modulation signal and the first pulse signal to obtain a first RF pulse modulation signal. A first multiplier to be generated; a second multiplier for multiplying the second ΔΣ modulation signal and the second pulse signal to generate a second RF pulse modulation signal; and the first and second RF pulse modulation signals. A switching amplifier for amplifying, is input to the switching amplifying unit, or the output from the switching amplifier section, and a combiner for combining said first and said second 2RF pulse modulated signal.

According to another embodiment, the transmitting apparatus includes a baseband signal generation unit that generates an in-phase component signal and a quadrature phase component signal of a baseband signal, and a first based on the in-phase component signal and the quadrature phase component signal. An IF signal generation unit that generates an intermediate frequency signal, a first pulse signal generation unit that converts the first carrier wave into a first pulse signal having a pulse waveform, and outputs the first carrier signal, and the first intermediate frequency signal is converted into the first pulse signal. A first ΔΣ modulator that performs ΔΣ modulation in synchronization and outputs a first ΔΣ modulation signal; a first multiplier that multiplies the first ΔΣ modulation signal and the first pulse signal to generate a first RF pulse modulation signal; A first switching amplifier for amplifying the first RF pulse modulation signal.

According to one embodiment, a control method of a transmission apparatus generates an in-phase component signal and a quadrature phase component signal of a baseband signal, and each of a first carrier and a second carrier that is 90 degrees out of phase with the first carrier. The first and second pulse signals having a pulse waveform are converted and output, and the in-phase component signal and the quadrature component signal are ΔΣ-modulated in synchronization with the first and second pulse signals, respectively. Output as a 2ΔΣ modulation signal, multiply the first ΔΣ modulation signal and the first pulse signal to generate a first RF pulse modulation signal, and multiply the second ΔΣ modulation signal and the second pulse signal to generate a second RF signal. Generate a pulse modulation signal, amplify the first and second RF pulse modulation signals using a switching amplifier, and input to the switching amplifier, or the switching amplifier The first and the second RF pulse modulation signals output from are synthesized.

According to another embodiment, a control method of a transmission device generates an in-phase component signal and a quadrature component signal of a baseband signal, and a first intermediate frequency signal based on the in-phase component signal and the quadrature component signal The first carrier wave is converted into a first pulse signal having a pulse waveform and output, and the first intermediate frequency signal is ΔΣ-modulated in synchronization with the first pulse signal and output as a first ΔΣ-modulated signal, A first RF pulse modulation signal is generated by multiplying the first ΔΣ modulation signal and the first pulse signal, and the first RF pulse modulation signal is amplified using a first switching amplifier.

According to the embodiment, it is possible to provide a transmission apparatus and a control method thereof that can suppress an increase in circuit scale.

3 is a block diagram illustrating a configuration example of a transmission apparatus according to Embodiment 1. FIG. 3 is a block diagram illustrating a specific configuration example of a transmission apparatus according to Embodiment 1. FIG. 6 is a timing chart illustrating a part of the operation of the transmission apparatus according to the first embodiment. 6 is a block diagram illustrating a first modification of the transmission apparatus according to Embodiment 1. FIG. 6 is a block diagram illustrating a second modification of the transmission apparatus according to Embodiment 1. FIG. 6 is a block diagram illustrating a configuration example of a transmission apparatus according to Embodiment 2. FIG. FIG. 10 is a block diagram showing a modification of the transmission apparatus according to Embodiment 2.

Hereinafter, embodiments will be described with reference to the drawings. Since the drawings are simple, the technical scope of the embodiments should not be narrowly interpreted based on the description of the drawings. Moreover, the same code | symbol is attached | subjected to the same element and the overlapping description is abbreviate | omitted.

In the following embodiments, when it is necessary for the sake of convenience, the description will be divided into a plurality of sections or embodiments. However, unless otherwise specified, they are not irrelevant to each other. Are partly or entirely modified, application examples, detailed explanations, supplementary explanations, and the like. Further, in the following embodiments, when referring to the number of elements (including the number, numerical value, quantity, range, etc.), especially when clearly indicated and when clearly limited to a specific number in principle, etc. Except, it is not limited to the specific number, and may be more or less than the specific number.

Furthermore, in the following embodiments, the constituent elements (including operation steps and the like) are not necessarily essential unless otherwise specified or apparently essential in principle. Similarly, in the following embodiments, when referring to the shapes, positional relationships, etc. of the components, etc., the shapes are substantially the same unless otherwise specified, or otherwise apparent in principle. And the like are included. The same applies to the above numbers and the like (including the number, numerical value, quantity, range, etc.).

<Embodiment 1>
FIG. 1 is a block diagram illustrating a configuration example of a transmission apparatus according to Embodiment 1. FIG. 2 is a block diagram illustrating a more specific configuration example of the transmission apparatus illustrated in FIG. FIG. 3 is a timing chart showing the operation of a part of the transmission apparatus shown in FIG. The transmission apparatus according to the present embodiment performs ΔΣ modulation on the in-phase component signal I and the quadrature component signal Q of the baseband signal in synchronization with the pulse signals P1 and P2 that are different in phase by 90 degrees, respectively, Multiplying by P2, RF pulse modulation signals R1 and R2 are generated. Thereafter, the RF pulse modulation signals R1 and R2 are amplified by the switching amplifier and synthesized by the synthesizer to obtain a transmission signal. Thereby, the transmission apparatus according to the present embodiment uses the in-phase component signal I and the quadrature component signal Q of the baseband signal as the RF signal in order to obtain the pulse signals P1 and P2 input to the ΔΣ modulator and the multiplier. Therefore, it is not necessary to provide a modulator (IQ modulator) that modulates the signal to the circuit, so that an increase in circuit scale can be suppressed and power consumption can be reduced. Hereinafter, a specific description will be given with reference to FIGS. 2 and 3.

A transmission device 1 shown in FIG. 2 is a transmission device in a communication device such as a mobile phone or a wireless LAN, for example, and includes an RF pulse modulation signal generation unit 10, a switching amplification unit 20, bandpass filters 13 and 14, And a synthesizer 15. The RF pulse modulation signal generation unit 10 includes a digital baseband signal generation unit (baseband signal generation unit) 101, a pulse signal generator (first pulse signal generation unit) 102, and a pulse signal generator (second pulse). Signal generator 103, ΔΣ modulator (first ΔΣ modulator) 104, ΔΣ modulator (second ΔΣ modulator) 105, multiplier (first multiplier) 106, and multiplier (second multiplier) 107. And an oscillator 108 and a phase shifter 109.

(Digital baseband signal generation unit 101)
Digital baseband signal generator 101 generates an in-phase component signal I and the quadrature component signal Q of the baseband signal S _BB. Note that the in-phase component signal I and the quadrature component signal Q of the baseband signal are digital signals that take a multilevel state.

(Oscillator 108 and phase shifter 109)
The oscillator 108 generates an oscillation signal having a frequency fc. The phase shifter 109 outputs a carrier wave CW1 that is in phase with the oscillation signal of the oscillator 108, and outputs a carrier wave CW2 that is 90 degrees out of phase with the carrier wave CW1.

(Pulse signal generators 102 and 103)
As shown in FIG. 3, the pulse signal generator 102 converts the carrier wave (first carrier wave) CW1 having the frequency fc into a pulse signal (first pulse signal) P1 having a pulse waveform and outputs the pulse signal. The pulse signal generator 103 converts a carrier wave (second carrier wave) CW2 having a phase difference of 90 degrees from the carrier wave CW1 into a pulse signal (second pulse signal) P2 having a pulse waveform and outputs the pulse signal.

The pulse signal generator 102 includes, for example, a comparator that indicates an H level (value “1”) when the carrier wave CW1 is greater than 0 and an L level (value “−1”) when the carrier wave CW1 is less than 0. Prepare. Similarly, the pulse signal generator 103 indicates, for example, an H level (value “1”) when the carrier wave CW2 is greater than 0, and an L level (value “−1”) when the carrier wave CW2 is less than 0. A comparator is provided.

(ΔΣ modulator 104, 105)
The ΔΣ modulator 104 ΔΣ modulates the in-phase component signal I of the baseband signal in synchronization with the pulse signal P1, and outputs it as a ΔΣ modulation signal (first ΔΣ modulation signal) M1. The ΔΣ modulator 105 performs ΔΣ modulation on the quadrature component signal Q of the baseband signal in synchronization with the pulse signal P2, and outputs it as a ΔΣ modulation signal (second ΔΣ modulation signal) M2.

As can be seen with reference to FIG. 3, the ΔΣ modulator 104 samples the multi-level in-phase component signal I in synchronization with the rising edge of the pulse signal P1, and generates a binary ΔΣ modulation signal M1 of 1 and −1. Convert and output. Similarly, the ΔΣ modulator 105 samples the multi-level quadrature phase component signal Q in synchronization with the rising edge of the pulse signal P2, converts it into a binary ΔΣ modulation signal M2 of 1, -1, and outputs it.

(Multipliers 106, 107)
Multiplier 106 multiplies ΔΣ modulation signal M1 output from ΔΣ modulator 104 and pulse signal P1, and outputs an RF pulse modulation signal (first RF pulse modulation signal) R1 upconverted to the RF band. Multiplier 107 multiplies ΔΣ modulation signal M2 output from ΔΣ modulator 105 and pulse signal P2, and outputs an RF pulse modulation signal (second RF pulse modulation signal) R2 upconverted to the RF band.

As can be seen from FIG. 3, when the value of the ΔΣ modulation signal M1 is “1”, the multiplier 106 sets “1” when the value of the pulse signal P1 is “1” and the pulse signal P1. When the value of “−1” is “−1”, “−1” is output. Further, when the value of the ΔΣ modulation signal M1 is “−1”, the multiplier 106 sets “−1” when the value of the pulse signal P1 is “1”, and sets the value of the pulse signal P1 to “−1”. In this case, “1” is output. The relationship between the ΔΣ modulation signal M2 and the pulse signal P2 and the RF pulse modulation signal R2 in the multiplier 107 is the same as the relationship between the ΔΣ modulation signal M1 and the pulse signal P1 and the RF pulse modulation signal R1 in the multiplier 106.

As described above, the pulse signals P1 and P2 are used as carrier signals for the

multipliers

106 and 107 and also as clock signals for the

ΔΣ modulators

104 and 105. As described above, by using the carrier signal and the clock signal in common, it is possible to prevent the synchronization deviation between the ΔΣ modulation signals M1 and M2 and the carrier signal.

(Switching amplifier 20)
The switching amplifier 20 includes a switching amplifier (first switching amplifier) 11 and a switching amplifier (second switching amplifier) 12.

The switching

amplifiers

11 and 12 are, for example, class D amplifiers or class E amplifiers, and are power amplifiers having high power efficiency. The switching

amplifiers

11 and 12 amplify the power of the RF pulse modulation signals R1 and R2, respectively, while maintaining their pulse waveforms.

(Bandpass filters 13, 14)
The band pass filter 13 passes a desired frequency band in the output of the switching amplifier 11. The band pass filter 14 passes a desired frequency band in the output of the switching amplifier 12.

The main purpose of the bandpass filters 13 and 14 is to reflect the quantization noise noise-shaved by the

ΔΣ modulators

104 and 105 included in the RF pulse modulation signals R1 and R2 amplified by the switching

amplifiers

11 and 12. It is to improve the power efficiency of signal amplification. Since noise-shaped quantization noise is small in the vicinity of the signal, it is not necessary to remove the quantization noise to the vicinity of the signal band using the bandpass filters 13 and 14. When it is necessary to remove a noise component in the vicinity of the transmission signal due to a wireless communication standard or the like, it can be removed by a duplexer (not shown) provided at the subsequent stage of the synthesizer 15.

(Synthesizer 15)
The synthesizer 15 synthesizes the outputs of the switching

amplifiers

11 and 12 that have passed through the bandpass filters 13 and 14 and outputs the synthesized signal as a transmission signal Dout.

That is, the transmission apparatus 1 amplifies and synthesizes the transmission signals (RF pulse modulation signals R1, R2) of the RF pulse modulation signal generation unit 10, and then outputs them as a transmission signal Dout. This transmission signal Dout is wirelessly transmitted to the outside via an antenna (not shown).

(a formula)
Next, the transmission signal Dout of the transmission device 1 illustrated in FIG. 2 will be described using a calculation formula.

First, the baseband signal _SBB is expressed as the following equation (1), where x is an in-phase component signal I, y is a quadrature component signal Q, and i is an imaginary unit.

Next, the carrier waves CW1 and CW2 are expressed by the following equations (2) and (3). Ω represents angular velocity, t represents time, and the amplitude is 1.

From Equation (1) and Equation (2), the RF pulse modulation signal R1 is expressed as the following Equation (4), omitting binarization by ΔΣ modulation. Further, from the equations (1) and (3), the RF pulse modulation signal R2 is expressed as the following equation (5), omitting binarization by ΔΣ modulation.

Therefore, the transmission signal Dout is expressed as the following equation (6).

Referring to the calculation formula, it can be seen that the transmission apparatus 1 generates a desired transmission signal.

As described above, the transmitting apparatus according to the present embodiment performs ΔΣ modulation on the in-phase component signal I and the quadrature component signal Q of the baseband signal in synchronization with the pulse signals P1 and P2 that are different in phase by 90 degrees, respectively. RF pulse modulation signals R1 and R2 are generated by multiplying the pulse signals P1 and P2. Thereafter, the RF pulse modulation signals R1 and R2 are amplified by the switching amplifier and synthesized by the synthesizer to obtain a transmission signal. As a result, the transmission apparatus according to the present embodiment modulates the in-phase component signal I and the quadrature component signal Q of the baseband signal into an RF signal in order to obtain a pulse phase signal input to the ΔΣ modulator and the mixer. Since there is no need to provide a modulator (IQ modulator) to increase, an increase in circuit scale can be suppressed. In addition, power consumption can be reduced.

In addition, the transmission apparatus according to the present embodiment may input pulse signals (P1, P2) having the same frequency as the carrier wave to the ΔΣ modulator and multiplier as the sampling clock and the carrier pulse signal, respectively. Even when the frequency is relatively high, it can operate normally with the sampling rate kept low. Since the sampling rate can be kept low, the power efficiency of the switching amplifier can be improved. In addition, since the common pulse signals (P1, P2) are input to the ΔΣ modulator and the multiplier, synchronization can be established between the ΔΣ modulator and the multiplier.

In the configuration disclosed in Patent Document 5, the quality of the transmission signal may be deteriorated due to the synchronization shift between the amplitude signal and the phase signal. On the other hand, such a problem does not occur in principle in the transmission apparatus according to the present embodiment.

(First Modification of Transmitter 1)
FIG. 4 is a block diagram illustrating a first modification of the transmission device 1 illustrated in FIG. 2 as a transmission device 1a. The transmitting apparatus 1a illustrated in FIG. 4 includes a bandpass filter 16 at the subsequent stage of the combiner 15 instead of including the bandpass filters 13 and 14 at the previous stage of the combiner 15. The other configuration of the transmission device 1a shown in FIG. 4 is the same as that of the transmission device 1 shown in FIG.

Even in this configuration, the same effect as that of the transmission device 1 shown in FIG. 2 can be obtained. In this configuration, since the number of band-pass filters is one as compared with the transmission device 1 shown in FIG. 2, the circuit can be simplified and the cost can be reduced.

(Second Modification of Transmitting Device 1)
FIG. 5 is a block diagram showing a second modification of the transmission apparatus 1 shown in FIG. 2 as a transmission apparatus 1b. The transmission apparatus 1b illustrated in FIG. 5 includes a switching amplification unit 20 at the subsequent stage of the combiner 15 instead of including the switching amplification unit 20 at the previous stage of the combiner 15. 5 includes a bandpass filter 16 at the subsequent stage of the switching amplifier 20, instead of including the bandpass filters 13 and 14 at the previous stage of the synthesizer 15. The transmission apparatus 1b illustrated in FIG. The switching amplifier 20 includes a switching amplifier 17 that amplifies the RF pulse modulation signals R1 and R2 synthesized by the synthesizer 15. The other configuration of the transmission device 1b shown in FIG. 5 is the same as that of the transmission device 1 shown in FIG.

Even in this configuration, the same effect as that of the transmission device 1 shown in FIG. 2 can be obtained. In this configuration, since there is one switching amplifier and one band-pass filter as compared with the transmission apparatus 1 shown in FIG. 2, the circuit can be simplified and the cost can be reduced.

<Embodiment 2>
FIG. 6 is a block diagram illustrating a configuration example of a transmission apparatus according to Embodiment 2. In FIG. A transmission device 1c illustrated in FIG. 6 includes an RF pulse modulation signal generation unit 10c, a switching amplifier (first switching amplifier) 11, and a bandpass filter 13. The RF pulse modulation signal generation unit 10c includes a digital baseband signal generation unit (baseband signal generation unit) 101, an IF signal generation unit 110, a pulse signal generator (first pulse signal generation unit) 102, and a ΔΣ modulator. 104, a multiplier (first multiplier) 106, and an oscillator 108.

The IF signal generation unit 110 generates the intermediate frequency signal IF1 based on the in-phase component signal I and the quadrature component signal Q of the baseband signal generated by the digital baseband signal generation unit 101. As the intermediate frequency signal IF1, one of the in-phase component and the quadrature component of the intermediate frequency signal obtained from the baseband signal is used. Here, the in-phase component is used as the intermediate frequency signal IF1. At this time, the intermediate frequency signal IF1 can be expressed as the following Expression (7).

Here, ω _IF is an angular velocity corresponding to the center frequency of the intermediate frequency signal IF1, t is time, x is an in-phase component signal I, and y is a quadrature component signal Q.

The pulse signal generator 102 converts the carrier wave CW1 generated by the oscillator 108 into a pulse signal (first pulse signal) P1 having a pulse waveform and outputs the pulse signal.

The ΔΣ modulator 104 ΔΣ modulates the intermediate frequency signal IF1 in synchronization with the pulse signal P1, and outputs it as a ΔΣ modulation signal (first ΔΣ modulation signal) M3.

Multiplier 106 multiplies ΔΣ modulation signal M3 output from ΔΣ modulator 104 and pulse signal P1, and outputs an RF pulse modulation signal (first RF pulse modulation signal) R3 upconverted to the RF band.

The switching amplifier 11 amplifies the power of the RF pulse modulation signal R3 while maintaining the pulse waveform.

The band-pass filter 13 passes a desired frequency band in the output of the switching amplifier 11 and outputs it as a transmission signal Dout. Here, the output of the switching amplifier 11 includes an image signal having the same level of power at a frequency opposite to that of the target signal and the carrier frequency. Therefore, the band pass filter 13 needs to remove the frequency band of the image signal.

That is, the transmission device 1c amplifies the transmission signal (RF pulse modulation signal R3) of the RF pulse modulation signal generation unit 10c, and then outputs it as the transmission signal Dout through the narrow band pass filter 13. This transmission signal Dout is wirelessly transmitted to the outside via an antenna (not shown).

Thus, as in the case of the transmission apparatus according to the first embodiment, the transmission apparatus according to the present embodiment uses the baseband signal of the baseband signal to obtain the pulse phase signal input to the ΔΣ modulator and the mixer. Since it is not necessary to provide a modulator (IQ modulator) that modulates the in-phase component signal I and the quadrature component signal Q into an RF signal, an increase in circuit scale can be suppressed. In addition, power consumption can be reduced. That is, the transmitting apparatus according to the present embodiment can achieve the same effect as that of the first embodiment.

(Modification of transmitter 1c)
FIG. 7 is a block diagram illustrating a modified example of the transmission device 1c illustrated in FIG. 6 as a transmission device 1d. 7 includes an RF pulse modulation signal generation unit 10d, a switching amplifier 11, a switching amplifier (second switching amplifier) 12, bandpass filters 13 and 14, and a combiner 15. The RF pulse modulation signal generation unit 10d includes a digital baseband signal generation unit (baseband signal generation unit) 101, an IF signal generation unit 111, a pulse signal generator 102, and a pulse signal generator (second pulse signal generation unit). ) 103, ΔΣ modulator 104, ΔΣ modulator 105, multiplier 106, multiplier (second multiplier) 107, oscillator 108, and phase shifter 109.

The IF signal generation unit 111 generates the intermediate frequency signal IF1 and the intermediate frequency signal IF2 based on the in-phase component signal I and the quadrature component signal Q of the baseband signal generated by the digital baseband signal generation unit 101. Here, out of the in-phase component and the quadrature component of the intermediate frequency signal obtained from the baseband signal, the in-phase component is used as the intermediate frequency signal IF1, and the quadrature component is used as the intermediate frequency signal IF2. At this time, the intermediate frequency signal IF2 can be expressed as the following Expression (8).

Of the in-phase and quadrature components of the intermediate frequency signal obtained from the baseband signal, when the quadrature component is used as the intermediate frequency signal IF1, the in-phase component is used as the intermediate frequency signal IF2.

The pulse signal generator 103 converts the carrier wave CW2 having a phase difference of 90 degrees from the carrier wave CW1 into a pulse signal (second pulse signal) P2 having a pulse waveform and outputs the pulse signal.

The ΔΣ modulator 105 ΔΣ modulates the intermediate frequency signal IF2 in synchronization with the pulse signal P2, and outputs it as a ΔΣ modulation signal (second ΔΣ modulation signal) M4.

Multiplier 107 multiplies ΔΣ modulation signal M4 output from ΔΣ modulator 105 and pulse signal P2, and outputs an RF pulse modulation signal (second RF pulse modulation signal) R4 upconverted to the RF band.

The switching amplifier 12 amplifies the power of the RF pulse modulation signal R4 while maintaining the pulse waveform.

The band pass filter 14 passes a desired frequency band in the output of the switching amplifier 12.

The synthesizer 15 synthesizes the outputs of the switching

amplifiers

11 and 12 that have passed through the band-

pass filters

13 and 14 and outputs the result as a transmission signal Dout. At this time, the above-described image signal is canceled. Therefore, it is not necessary to narrow the

bandpass filters

13 and 14 for image signal removal.

The other configuration and operation of the transmission device 1d shown in FIG. 7 are the same as those of the transmission device 1c shown in FIG.

Also in this configuration, the same effect as the transmission device 1c shown in FIG. 6 can be obtained.

As described above, in order to obtain the pulse phase signal input to the ΔΣ modulator and the mixer, the transmission apparatus according to

Embodiments

1 and 2 described above includes the in-phase component signal I and the quadrature component signal Q of the baseband signal. Since it is not necessary to provide a modulator (IQ modulator) that modulates the signal to an RF signal, an increase in circuit scale can be suppressed. In addition, power consumption can be reduced.

In addition, the transmitting apparatuses according to the first and second embodiments may input pulse signals (P1, P2) having the same frequency as the carrier wave to the ΔΣ modulator and multiplier as the sampling clock and the carrier pulse signal, respectively. Even when the frequency of the carrier wave is relatively high, it can operate normally with the sampling rate kept low. Moreover, since the sampling rate can be kept low, the power efficiency of the switching amplifier can be improved. In addition, since the common pulse signals (P1, P2) are input to the ΔΣ modulator and the multiplier, synchronization can be established between the ΔΣ modulator and the multiplier.

The present invention has been described above with reference to the embodiment, but the present invention is not limited to the above. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the invention.

This application claims priority based on Japanese Patent Application No. 2014-15816 filed on January 30, 2014, the entire disclosure of which is incorporated herein.

1, 1a to

1d Transmitters

10, 10c, 10d RF pulse

modulation signal generator

11, 12, 17

Switching amplifier

13, 14, 16 Bandpass filter 15 Synthesizer 20 Switching amplifier 101 Digital

baseband signal generator

102, 103 Pulse signal generator 104 ΔΣ modulator 105

ΔΣ modulator

106, 107 multiplier 108 Oscillator 109

Phase shifter

110, 111 IF signal generator

Claims

Baseband signal generation means for generating an in-phase component signal and a quadrature phase component signal of the baseband signal;
First and second pulse signal generating means for converting the first carrier wave and the second carrier wave having a phase difference of 90 degrees from the first carrier wave into first and second pulse signals each having a pulse waveform;
First and second ΔΣ modulation means for performing ΔΣ modulation on the in-phase component signal and the quadrature phase component signal in synchronization with the first and second pulse signals, respectively, and outputting the first and second ΔΣ modulation signals;
First multiplication means for multiplying the first ΔΣ modulation signal and the first pulse signal to generate a first RF pulse modulation signal;
Second multiplication means for multiplying the second ΔΣ modulation signal and the second pulse signal to generate a second RF pulse modulation signal;
Switching amplification means for amplifying the first and second RF pulse modulation signals;
A transmission apparatus comprising: combining means for combining the first and second RF pulse modulation signals that are input to the switching amplification means or output from the switching amplification means.
The switching amplification means includes
First and second switching amplification means for amplifying the first and second RF pulse modulation signals, respectively;
The transmitting apparatus according to claim 1, wherein the combining unit combines the outputs of the first and second switching amplification units.
The synthesizing unit synthesizes the first and second RF pulse modulation signals input to the switching amplification unit,
The switching amplification means includes
The transmission apparatus according to claim 1, further comprising a switching amplification unit that amplifies the first and second RF pulse modulation signals synthesized by the synthesis unit.
Baseband signal generation means for generating an in-phase component signal and a quadrature phase component signal of the baseband signal;
IF signal generating means for generating a first intermediate frequency signal based on the in-phase component signal and the quadrature component signal;
First pulse signal generating means for converting the first carrier wave into a first pulse signal having a pulse waveform and outputting the first pulse signal;
First ΔΣ modulation means for performing ΔΣ modulation on the first intermediate frequency signal in synchronization with the first pulse signal and outputting the first intermediate frequency signal as a first ΔΣ modulation signal;
First multiplication means for multiplying the first ΔΣ modulation signal and the first pulse signal to generate a first RF pulse modulation signal;
And a first switching amplification means for amplifying the first RF pulse modulation signal.
The transmission device according to claim 4, further comprising a bandpass filter that allows a desired band to pass among outputs of the first switching amplification means.
5. The IF signal generation unit generates one of an in-phase component and a quadrature component of an intermediate frequency signal generated based on the in-phase component signal and the quadrature component signal as the first intermediate frequency signal. Or the transmitting apparatus of 5.
The IF signal generation means further generates a second intermediate frequency signal based on the in-phase component signal and the quadrature component signal,
The transmitter is
A second pulse signal generating means for converting and outputting a second carrier wave having a phase difference of 90 degrees from the first carrier wave to a second pulse signal having a pulse waveform;
Second ΔΣ modulation means for performing ΔΣ modulation on the second intermediate frequency signal in synchronization with the second pulse signal and outputting the second intermediate frequency signal as a second ΔΣ modulation signal;
Second multiplication means for multiplying the second ΔΣ modulation signal and the second pulse signal to generate a second RF pulse modulation signal;
Second switching amplification means for amplifying the second RF pulse modulation signal;
The transmission apparatus according to claim 4, further comprising a combining unit that combines the outputs of the first and second switching amplification units.
The IF signal generating means generates one of the in-phase component and the quadrature component of the intermediate frequency signal generated based on the in-phase component signal and the quadrature component signal as the first intermediate frequency signal, and The transmission device according to claim 7, wherein the other of the in-phase component and the quadrature component of the intermediate frequency signal is generated as the second intermediate frequency signal.
Generate in-phase and quadrature component signals of the baseband signal,
The first carrier wave and the second carrier wave that is 90 degrees out of phase with the first carrier wave are respectively converted into first and second pulse signals having a pulse waveform and output,
The in-phase component signal and the quadrature phase component signal are ΔΣ-modulated in synchronization with the first and second pulse signals, respectively, and output as first and second ΔΣ-modulated signals,
Multiplying the first ΔΣ modulation signal and the first pulse signal to generate a first RF pulse modulation signal,
Multiplying the second ΔΣ modulation signal and the second pulse signal to generate a second RF pulse modulation signal;
Amplifying the first and second RF pulse modulated signals using switching amplification means;
A method for controlling a transmitting apparatus, comprising: combining the first and second RF pulse modulation signals that are input to the switching amplification unit or output from the switching amplification unit.
Amplifying the first and second RF pulse modulation signals using first and second switching amplification means provided in the switching amplification means;
The method of controlling a transmitting apparatus according to claim 9, wherein the outputs of the first and second switching amplifiers are combined.
Combining the first and second RF pulse modulation signals input to the switching amplification means;
The method for controlling the transmission apparatus according to claim 9, wherein the synthesized first and second RF pulse modulated signals are amplified using the switching amplification means.
Generate in-phase and quadrature component signals of the baseband signal,
Generating a first intermediate frequency signal based on the in-phase component signal and the quadrature component signal;
The first carrier wave is converted into a first pulse signal having a pulse waveform and output,
The first intermediate frequency signal is ΔΣ-modulated in synchronization with the first pulse signal, and output as a first ΔΣ-modulated signal,
Multiplying the first ΔΣ modulation signal and the first pulse signal to generate a first RF pulse modulation signal,
A control method of a transmitting apparatus, wherein the first RF pulse modulation signal is amplified using first switching amplification means.
The method for controlling a transmitting apparatus according to claim 12, wherein a desired band of the output of the first switching amplification means is passed using a band-pass filter.
The transmission device according to claim 12 or 13, wherein one of an in-phase component and a quadrature component of an intermediate frequency signal generated based on the in-phase component signal and the quadrature component signal is generated as the first intermediate frequency signal. Control method.
Generating a second intermediate frequency signal based on the in-phase component signal and the quadrature component signal;
A second carrier wave having a phase difference of 90 degrees from the first carrier wave is converted into a second pulse signal having a pulse waveform and output;
The second intermediate frequency signal is ΔΣ-modulated in synchronization with the second pulse signal and output as a second ΔΣ-modulated signal,
Multiplying the second ΔΣ modulation signal and the second pulse signal to generate a second RF pulse modulation signal;
Amplifying the second RF pulse modulation signal using second switching amplification means;
The transmission apparatus control method according to claim 12, wherein the outputs of the first and second switching amplification units are combined.
One of the in-phase component and the quadrature component of the intermediate frequency signal generated based on the in-phase component signal and the quadrature component signal is generated as the first intermediate frequency signal, and the in-phase component of the intermediate frequency signal and The method for controlling the transmission device according to claim 15, wherein the other of the quadrature components is generated as the second intermediate frequency signal.