Amplifier and amplification method

Abstract

An amplifier (300) comprising: a first signal path comprising a first amplifier circuit (105A) configured to receive a first signal (RF1) having a frequency and having a phase and amplitude at the frequency that can vary; a second signal path comprising a second amplifier circuit (105B) configured to receive a second signal (RF2) having the frequency, wherein at least one of a relative phase and amplitude of the second signal is fixed at the frequency; a combiner circuit (106) configured to combine outputs of the first amplifier circuit and the second amplifier circuit.

Description

Technical Field

[0001] This disclosure relates to an amplifier. Background Technology

[0002] The provided "background" description is intended to present the overall context of this disclosure. Within the scope of the background description, the work of the currently named inventor and descriptions that may not conform to the prior art at the time of submission are neither expressly nor impliedly acknowledged as prior art in this disclosure.

[0003] Power amplifiers (which can simply be called amplifiers) are used in many applications to increase the power of signals. An example application is amplifying radio signals transmitted by base stations or terminal equipment in wireless telecommunications networks. There is a desire to improve the power efficiency of such amplifiers to reduce power consumption. There is also a desire to reduce the complexity of such amplifiers to lower their cost and make them easier to install. Summary of the Invention

[0004] This disclosure is defined by the content of the technical solution. Attached Figure Description

[0005] The non-limiting embodiments and advantages of this disclosure can be better understood by referring to the following detailed description taken in conjunction with the accompanying drawings, in which:

[0006] Figure 1 A known amplifier 100 is schematically shown;

[0007] Figures 2A to 2C It exhibits different amplifier efficiencies at different amplitudes and phases;

[0008] Figure 3 An amplifier according to a first embodiment is schematically shown;

[0009] Figure 4 An amplifier according to the second embodiment is schematically shown;

[0010] Figures 5A to 5D The efficiency of the amplifier for different amplitudes and / or relative phases of signals propagating along the second signal path 104B is shown.

[0011] Figure 6 A first variant of the second embodiment is schematically shown;

[0012] Figure 7 A second variant of the second embodiment is schematically shown;

[0013] Figure 8 A third variant of the second embodiment is schematically shown;

[0014] Figure 9 A fourth variant of the second embodiment is schematically shown;

[0015] Figure 10 An example device 1000 is schematically shown, which may include the amplifiers of this disclosure; and

[0016] Figure 11 A method according to an embodiment is shown.

[0017] Similar reference numerals indicate the same or corresponding parts throughout the accompanying drawings. Detailed Implementation

[0018] Figure 1 A known amplifier 100 is shown. Input baseband signals I & Q. in The (in-phase and quadrature) signals are received by a signal splitter circuit (not shown) and split into a first signal and a second signal. The first signal and the second signal are transmitted along separate first signal paths and second signal paths 104A and 104B, respectively.

[0019] On the first signal path 104A, digital predistortion (DPD) is performed on the first signal by DPD circuit 103 (this is optional). Then, a first complex nonlinear drive function (NLDF) 1 is performed on the first signal by first complex nonlinear drive function (NLDF) circuit 102A. NLDF1 is performed on the first signal while it is still in baseband I&Q form. The first signal is then converted to a first radio frequency (RF) signal RF1 (using any suitable circuit (not shown) to convert the first signal from digital to analog, modulate the carrier, and up-convert to generate RF1). NLDF1 defines the phase and amplitude of RF1 for a given amplifier output power and frequency. The phase and amplitude of RF1 for a given amplifier output power and frequency can be adjusted by adjusting one or more parameters of NLDF1. For example, NLDF1 can be implemented using a lookup table, piecewise function, or polynomial function. RF1 is then amplified by first power amplifier circuit (first power amplifier) ​​105A and passed to combiner circuit 106.

[0020] On the second signal path 104B, the second complex nonlinear drive function NLDF2 is executed on the second signal by the second complex nonlinear drive function circuit 102B. NLDF2 is executed on the second signal while the first signal is still in baseband I&Q form. The second signal is then converted into a second radio frequency (RF) signal RF2 (using any suitable circuit (not shown) to convert the first signal from digital to analog, modulate the carrier, and up-convert to generate RF2). NLDF2 defines the phase and amplitude of RF2 at a given amplifier output power and frequency. For a given amplifier output power and frequency, the phase and amplitude of RF2 can be adjusted by adjusting one or more parameters of NLDF2. For example, NLDF2 can be implemented using a lookup table, a piecewise function, or a polynomial function. RF2 is then amplified by the second power amplifier circuit (second power amplifier) ​​105B and passed to the combiner circuit 106.

[0021] Combiner circuit 106 combines RF1 and RF2 to generate the output RF signal RF out RF out It can be received by a receiver (not shown). At the receiver, the output RF signal is down-converted, demodulated, and converted from analog to digital to obtain the baseband signal again (this can be referred to as I&Q). out ).

[0022] For simplicity, the described embodiments may be discussed as RF signals “output” by the NLDF circuit. However, in reality, the NLDF circuit outputs an I&Q baseband signal (because an I&Q baseband signal is input), and then uses suitable additional circuitry (not shown) to convert it into an RF signal to convert the first signal from digital to analog, modulate the carrier, and up-convert the frequency to generate the RF signal. Therefore, this is what it means when the NLDF circuit is referred to as “outputting” an RF signal. The details of the signal conversion from I&Q baseband to RF are known in the art and will not be described in detail here.

[0023] In the example, each of the first amplifier circuit and the second amplifier circuits 105A and 105B performs one of the functions of a carrier amplifier and a peak amplifier, respectively, in an inverse Doherty amplifier, and the combiner circuit 106 performs the function of a combiner for the inverse Doherty amplifier. Specifically, the first amplifier circuit 105A can perform the function of a carrier amplifier, and the second amplifier circuit 105B can perform the function of a peak amplifier. Alternatively, the first amplifier circuit 105A can perform the function of a peak amplifier, and the second amplifier circuit 105B can perform the function of a carrier amplifier. This is predetermined and depends on the physical structure and characteristics of the amplifier.

[0024] In the example, the DPD circuit (if present), the first complex NLDF circuit 102A, and the second complex NLDF circuit 102B are included within the digital signal processor (DSP) 101.

[0025] By appropriately adjusting the amplitude and phase of each of RF1 and RF2, an improved power efficiency of amplifier 100 at a given output power stage can be observed. This is as follows: Figures 2A to 2C shown. Specifically, Figure 2C This is generated by adjusting the RF1 amplitude, RF2 amplitude, and RF2 phase relative to RF1 (this is called the relative phase of RF2) of each output power stage within the output power stage range, and measuring the amplifier efficiency of each output power stage, the combination of RF1 amplitude, RF2 amplitude, and RF2 phase. The maximum efficiency achieved for each output power stage is shown in lines 201 and 202. Line 201 shows the maximum DCRF efficiency for each output power stage (based on DC input power and RF output power). Line 202 shows the maximum power-added efficiency (PAE) at each output power stage. Figure 2C Line 200 shows the gain of amplifier 100 at each output power stage when the amplitudes of RF1, RF2, and RF2 are adjusted to provide maximum efficiency. Figure 2A and Figure 2B The display shows the RF1 power 203, RF2 power 204, and RF2 phase 205 at each output power stage that provides maximum efficiency. Figure 2A The power of RF1 and RF2 using normalized ratios is shown, and the phase of RF2 relative to RF1 is also shown. Figure 2B The power of RF1 and RF2 is shown in dBm, and the original measured phase of RF2 is also displayed. Note that this is for input signals I & Q with a fixed predetermined frequency. in generate Figures 2A to 2C .

[0026] While the efficiency of amplifier 100 can be improved by appropriately adjusting the amplitude / power and phase of each of RF1 and RF2, providing the circuitry to allow this increases the amplifier's complexity. Therefore, a high-efficiency amplifier with reduced complexity is needed, or at least a balance between increased efficiency and reduced complexity that is more easily achieved depending on the application of the amplifier.

[0027] Figure 3Amplifier 300 according to an embodiment is shown. Amplifier 300 is identical to amplifier 100 except that the second complex NLDF circuit 102B is replaced by a real NLDF circuit 301, such that NLDF2 is a real (not complex) linear driving function. Real nonlinear driving functions are generally more complex than complex nonlinear driving functions. Therefore, using real NLDF2 reduces the complexity of amplifier 300. Real NLDF2 allows the phase or amplitude (but not both) of RF2 to be adjusted by regulating one or more parameters of real NLDF2. Therefore, the efficiency of amplifier 300 can be improved within the constraint of a fixed phase or amplitude of RF2 by regulating other non-fixed phases or amplitudes (as well as regulating the phase and amplitude of RF1). For example, like complex NLDF2, real NLDF2 is implemented using lookup tables, piecewise functions, or polynomial functions (but only with real, not complex, coefficients). Therefore, amplifier 300 allows for an improved balance between amplifier efficiency and complexity.

[0028] Figure 4 Amplifier 400 according to another embodiment is shown. Amplifier 400 is identical to amplifier 100, except that the only NLDF circuit is a complex NLDF circuit 102A, NLDF1, and input signals I&Q that perform the following operations. in The signal is not splittered before being passed to DPD circuit 103 (if present) and complex NLDF circuit 102A. Instead, RF1 output from NLDF circuit 102A is splittered by signal splitter circuit (not shown) to generate first and second RF signals that are passed along first signal path and second signal path 104A and 104B, respectively. The first RF signal is amplified by first power amplifier circuit 105A and passed to combiner circuit 106 in the same manner as RF1 in amplifiers 100 and 300. However, the second RF signal is processed by signal processing circuit 401 before being amplified by second power amplifier circuit 105B and passed to combiner circuit 106. For a specific frequency input signal I&Q... in The signal processing circuit 401 keeps at least one of the amplitude of the second RF signal and the phase of the second RF signal relative to the first RF signal (this is referred to as the relative phase of the second RF signal) constant. An example of the signal processing circuit 401 will be described later.

[0029] Figure 4The arrangement allows the single signal RF1 output from the complex NLDF circuit 102A to generate two signals that travel along separate signal paths 104A and 104B of the amplifier 400. Therefore, the second NLDF circuit 102B or 301 may not be present in the amplifier 400 at all, thus reducing the complexity of the amplifier 400. As previously mentioned, the phase and amplitude of the first RF signal separated from RF1 and transmitted along the first signal path 104A can be adjusted by adjusting one or more parameters of the NLDF1. However, at least one of the amplitude and relative phase of the second RF signal separated from RF1 is fixed by the signal processing circuit 401. Therefore, the efficiency of the amplifier 400 can be improved within the constraints of the fixed amplitude and / or relative phase of the second RF signal (while adjusting the phase and amplitude of the first RF signal). Thus, the amplifier 400 allows for an improved balance between amplifier efficiency and complexity.

[0030] Amplifier 400 is particularly suitable for applications such as wireless telecommunications base stations, where the input to amplifier 400 is a single baseband signal that cannot be regulated by the supplier of amplifier 400. In this case, amplifier 400 does not include DSP 101; instead, DSP 101 is provided upstream of amplifier 400 by the base station supplier. Amplifier 400 can be easily installed in existing base stations because it can be connected to DSP 101 (which acts as a...) Figure 4 The single baseband signal output by RF1 in the middle.

[0031] Figures 5A to 5D This shows the amplifier's response to an input signal I&Q at a predetermined frequency. in And for along the first signal path 104A (e.g.) Figure 3 RF1 or Figure 4 The amplifier efficiency of the first branch RF signal in the second signal path 104B (e.g.) Figure 3 RF2 or Figure 4 The second branch RF signal in the output power path 104A has different amplitudes and / or relative phases, and at each output power level within the output power level range, the first signal path 104A has a fixed amplitude and phase. The darker point 501 represents DCRF efficiency, and the brighter point 502 represents PAE.

[0032] Figure 5A It is generated by adjusting the amplitude and relative phase of the signal propagating along the second signal path 104B and measuring the efficiency of the amplifier for each output power stage, amplitude and phase combination. Figure 5B It is generated by adjusting only the relative phase of the signal propagating along the second signal path 104B (keeping the amplitude constant) and measuring the amplifier efficiency of each output power stage and phase combination. Figure 5CIt is generated by adjusting only the amplitude of the signal moving along the second signal path 104B (keeping the relative phase constant) and measuring the amplifier efficiency of each output power stage and phase combination. Figure 5D It is generated for constant amplitude and relative phase. Therefore, the amplifier efficiency is constant for each power level.

[0033] therefore, Figures 5A to 5D This demonstrates a balance between more control over amplifier efficiency (and thus potentially greater improvements in amplifier efficiency) and higher complexity, and less control over amplifier efficiency (and thus potentially less improvements in amplifier efficiency) and lower complexity. Specifically, Figure 5A It represents the highest efficiency control, but also the highest complexity (because the amplitude and relative phase of the signal propagating along the second signal path 104B need to be adjustable). Figure 5D This represents the least efficient but least complex control (because the amplitude and relative phase of the signal propagating along the second signal path 104B are fixed). Figure 5B and Figure 5C express Figure 5A and Figure 5D The level of efficiency control between them, and Figure 5A and Figure 5D The complexity arises because only one of the amplitude and relative phase of the signal propagating along the second signal path 104B needs to be adjusted. This can be achieved using a known amplifier 100. Figure 5A The efficiency distribution is shown. Figure 5B or Figure 5C The efficiency distribution shown can be achieved by amplifier 300. Similarly... Figure 5D The efficiency curve can be achieved by amplifier 400. Therefore, this technology provides an amplifier in which higher efficiency control (e.g., amplifier 300) or better reduction of complexity (e.g., amplifier 400) can be selected depending on the application of the amplifier.

[0034] Figure 6A first variant 400A of amplifier 400 is shown. First and second RF signals are generated by splitter circuit 601. Signal processing circuit 401 on the second signal path 104B includes a driver amplifier circuit (driver) 602, followed by a voltage limiter circuit (limiter) 603. The second RF signal is first amplified by driver 602. Its amplitude is then limited by limiter 603. The amplification amount of the driver and the amplitude limit of the limiter are determined such that the processed second RF signal output by the limiter has a constant amplitude. In this example, the amplification amount and amplitude limit are determined such that the average peak amplitude of the second RF signal is within the amplitude limit, and that the second amplifier 105B remains saturated (e.g., the saturated output power of the second amplifier 105B may be only about 10% of the saturated output power of the first amplifier 105A). The relative phase of the second RF signal is fixed by the length of the second signal path 104B (thus setting a fixed phase delay). Therefore, the second RF signal of amplifier 400A has a fixed amplitude and a fixed relative phase. In this example, amplifier 400A is adapted to work with input signals I&Q having a fixed predetermined frequency. in Used together for the input signal I&Q in The fixed amplitude and fixed relative phase of the second RF signal can be predetermined to improve amplifier efficiency.

[0035] Figure 7 A second variant 400B of amplifier 400 is shown. Amplifier 400B is identical to amplifier 400A, except that the signal processing circuit 401 further includes a controllable phase shift circuit (phase shifter) 701 for controlling the relative phase of the second RF signal. The phase shifter 701 is placed in... Figure 7 The limiter 603 is located after the second signal path 104B, but can be placed at other locations on the second signal path 104B (e.g., before the driver 602). For example, the phase shifter 701 includes suitable circuitry that allows the length of the second signal path 104B to be varied (to provide a variable phase delay) to control the relative phase of the second RF signal. Thus, although the amplitude of the second RF signal of amplifier 400B remains fixed, the relative phase of the second RF signal is controllable.

[0036] In the example, amplifier 400B is suitable for input signals I&Q with a variable RF transmission frequency. in For the input signal I&Q inThe fixed amplitude of the second RF signal is predetermined, but the relative phase of the second RF signal can vary according to the RF frequency to improve amplifier efficiency (because the optimal effective relative phase of the second RF signal varies with the input signal frequency). The frequency can vary continuously or discretely, and correspondingly, the relative phase of the second RF signal can vary continuously or discretely. The relationship between the input signal frequency and the relative phase of the second RF signal is indicated by a lookup table, mathematical function, etc., predetermined (e.g., by experiment or computer modeling) and stored in a storage medium (not shown). For example, a phase shifter 701 is controlled by suitable processing circuitry (not shown) to adjust the relative phase of the second RF signal according to the input signal frequency and the relationship. The storage medium and processing circuitry are included in a device (e.g., a base station) including, for example, amplifier 400B.

[0037] In the example, the input signals I & Q in The baseband frequency can be selected from several discrete predetermined values. The relative phase of the second RF signal is then adjusted according to the selected baseband frequency to improve the amplifier efficiency for the selected baseband frequency. This allows for improved amplifier efficiency compared to having a fixed relative phase for RF signals used for all baseband frequencies.

[0038] In the example (which can be combined with the example in the previous paragraph), the input signals I & Q in It is a frequency-modulated signal, and the relative phase of the second RF signal is continuously adjusted in real time according to the modulation of the input signal frequency. Compared with a second RF signal having a fixed relative phase for the frequency-modulated signal, this allows for improved amplifier efficiency.

[0039] Figure 8 A third variant 400C of amplifier 400 is shown. Amplifier 400C is the same as amplifier 400B, except that the signal processing circuit 401 additionally includes a controllable amplitude adjustment circuit (amplitude regulator) 801 for controlling the amplitude of the second RF signal. Amplitude regulator 801 is Figure 8 The variable gain amplifier (VGA) in the image is used, but this disclosure is not limited thereto. For example, the amplitude modulator 801 may be an attenuator. The amplitude modulator 801 is placed in... Figure 8 The phase shifter 701 is located after the limiter 603 and before the phase shifter 701 on the second signal path 104B, and can be placed at other locations on the second signal path 104B (e.g., after the phase shifter 701). Therefore, in addition to the relative phase of the second RF signal being controllable, the amplitude of the second RF signal is also controllable in the amplifier 400C. In an alternative embodiment, the phase shifter 701 can be omitted from the amplifier 400C. In this case, although the relative phase of the second RF signal is determined in advance and kept fixed, the amplitude of the second RF signal is controllable.

[0040] In the example, amplifier 400C is adapted to input signals I&Q with a variable RF transmission frequency. in Used together for the input signal I&Q in The amplitude of the second RF signal can vary according to the RF frequency to improve amplifier efficiency (because the optimal effective amplitude of the second RF signal varies according to the input signal frequency). The frequency can vary continuously or discretely, and correspondingly, the amplitude of the second RF signal can vary continuously or discretely. The relationship between the input signal frequency and amplitude of the second RF signal is indicated by a lookup table, mathematical function, etc., predetermined (e.g., by experiment or computer modeling) and stored in a storage medium (not shown). For example, an amplitude modulator 801 is controlled by suitable processing circuitry (not shown) to adjust the amplitude of the second RF signal according to the input signal frequency and relationship. The storage medium and processing circuitry are included in a device (e.g., a base station) including, for example, an amplifier 400C.

[0041] In the example, the input signals I & Q in The baseband frequency can be selected from several discrete predetermined values. The amplitude of the second RF signal is then adjusted according to the selected baseband frequency to improve the amplifier efficiency at the selected baseband frequency. This improves amplifier efficiency compared to having a fixed RF signal amplitude for all baseband frequencies.

[0042] In the example (which can be combined with the example in the previous paragraph), the input signals I & Q in It is a frequency-modulated signal, and the amplitude of the second RF signal is continuously and in real time adjusted according to the modulation of the input signal frequency. Compared with a fixed amplitude for a second RF signal used for frequency modulation, this allows for improved amplifier efficiency.

[0043] Figure 9 A fourth variant 400D of amplifier 400 is shown. Amplifier 400D has signal processing circuitry 401 of amplifier 400A, 400B or 400C (or any other variant), but also includes a controllable DC power supply 901 for controlling the DC voltage supplied to the second power amplifier 105B.

[0044] In the example, amplifier 400D is adapted to input signals I&Q with a variable RF transmission frequency. in Used together for the input signal I&Q in The DC voltage supplied to the second power amplifier 105B can vary according to the RF frequency to improve amplifier efficiency (because the optimal effective DC voltage varies according to the input signal frequency). The frequency can vary continuously or discretely (in... Figure 9In the example, the frequency varies discretely between Vd1 and Vdn, and correspondingly, the DC voltage can vary continuously or discretely. For example, the relationship between the input signal frequency and the DC voltage is indicated by a lookup table, mathematical function, etc., predetermined (e.g., through experimental or computer modeling) and stored in a storage medium (not shown). For example, a controllable DC voltage power supply 901 is controlled by suitable processing circuitry (not shown) to adjust the DC voltage according to the input signal frequency and relationship. The storage medium and processing circuitry are included within a device (e.g., a base station) including, for example, an amplifier 400D.

[0045] In the example, the input signals I & Q in The baseband frequency can be selected from several discrete predetermined values. The DC voltage is then adjusted according to the selected baseband frequency to improve the amplifier efficiency at that frequency. This improves amplifier efficiency compared to having a fixed DC voltage for all baseband frequencies.

[0046] In the example (which can be combined with the example in the previous paragraph), the input signals I & Q in It is a frequency-modulated signal, and the DC voltage is continuously adjusted in real time according to the modulation of the input signal frequency. This allows for improved amplifier efficiency compared to having a fixed DC voltage for a frequency-modulated signal.

[0047] Therefore, the amplifiers of this disclosure can be easily and flexibly configured to balance efficiency and complexity according to the requirements of each specific use case. For example, if minimal complexity is paramount, then variant 400A may be the most suitable. On the other hand, if maximum efficiency is paramount, then variant 400D, with signal processing circuitry 401 of variant 400C and based on input signals I&Q... in Modulation to adjust the amplitude and relative phase of the second RF signal is likely most suitable. To balance efficiency and complexity, variants 400B or 400C (which modulate or not modulate the amplitude and / or relative phase of the second RF signal according to the input signal frequency) are likely most suitable. However, in all cases, complexity is reduced compared to the known amplifier 100 because the second complex NLDF circuit 102B is no longer required.

[0048] Figure 10A device 1000, which may include the amplifiers of this disclosure, is shown. For example, device 1000 may be a wireless telecommunications base station (e.g., a macrocell, microcell, small cell, femtocell, or picocell) or a terminal device. The device includes: a transceiver 1001 for transmitting and / or receiving RF signals; a processor 1002 for processing electronic instructions; a memory 1003 for storing electronic instructions to be processed and input and output data associated with the electronic instructions; and a storage medium 1004 (e.g., in the form of a hard disk drive, solid-state drive, magnetic tape drive, etc.) for long-term storage of digital information. For example, each of the transceiver 1001, processor 1002, memory 1003, and storage medium 1004 is implemented using suitable circuitry. The processor 1002 controls the operation of each of the transceiver 1001, memory 1003, and storage medium 1004. The amplifier disclosed herein is included within a transceiver 1001, and when adjustable, is configured by a processor 1002 according to relational information (e.g., lookup table, mathematical function, etc.) stored in a storage medium 1004 (as previously described) for the input signals I and Q. in The different frequency adjustment amplitudes, the relative phase of the second signal path 104B, and / or the DC voltage.

[0049] Figure 11 A method according to an embodiment is illustrated. The method is performed by an amplifier of this disclosure. The method begins at step 1100. In step 1101, the first amplifier circuit 105A of the first signal path 104A receives a first signal (e.g., Figure 3 RF1 in or from Figure 4 The first RF signal (RF1 separated in the first RF signal) has a frequency and a phase and amplitude that can vary at that frequency. That is, even if the frequency does not change, the phase and amplitude can be adjusted, for example, by a complex NLDF circuit 102A. In step 1102 (which may occur simultaneously with step 1101), the second signal (e.g. Figure 3 RF2 in or from Figure 4 The second RF signal (separated from RF1 in the first signal path 104B) is received by the second amplifier circuit 105B. The second signal has the same frequency as the first signal. However, at least one of the relative phase and amplitude of the second signal is fixed at that frequency. That is, the fixed relative phase and / or amplitude cannot be adjusted when the frequency remains constant. This is achieved by using a real-valued nonlinear distortion function circuit 301 (where the relative phase or amplitude remains the same for all frequencies) or a signal processing circuit 401, where the relative phase and / or amplitude (if adjustable) is adjustable only when the frequency changes (e.g., by a change in the baseband frequency or due to the input signal I&Q). in (Frequency modulation). In an embodiment, this is achieved by splitting the input signals I and Q from a single input signal. inThe derived signals are used to generate the first and second signals. In step 1103, the outputs of the first and second amplifier circuits are combined to generate the output signal RF. out The method ends at step 1104.

[0050] Some embodiments of this technology are defined by the following numbered clauses:

[0051] 1. An amplifier, comprising:

[0052] The first signal path includes a first amplifier circuit, which is configured to receive a first signal having a frequency and having a phase and amplitude that can vary at that frequency.

[0053] The second signal path includes a second amplifier circuit configured to receive a second signal having a frequency, wherein at least one of the relative phase and amplitude of the second signal is fixed at the frequency.

[0054] The combiner circuit is configured to combine the outputs of the first amplifier circuit and the second amplifier circuit.

[0055] 2. The amplifier according to Clause 1, wherein the first signal and the second signal are obtained by splitting a single input signal.

[0056] 3. The amplifier according to Clause 2, wherein the phase and amplitude of the first input signal at a frequency are variable using a complex nonlinear drive function.

[0057] 4. The amplifier according to Clause 3, wherein:

[0058] The phase and amplitude of the first input signal can vary at frequency after being split into individual input signals; and

[0059] After the input signal is splittered using a real nonlinear driving function, only one of the relative phase and amplitude of the second input signal can change at the frequency.

[0060] 5. The amplifier according to Clause 3, wherein:

[0061] The phase and amplitude of the first input signal can vary at frequency before the individual input signals are split;

[0062] The second signal path has a phase delay to fix the relative phase of the second signal at the frequency; and

[0063] The second signal path includes a third amplifier circuit, followed by an amplitude limiter to fix the amplitude of the second signal at a specific frequency.

[0064] 6. The amplifier according to Article 5, wherein the second signal path includes a phase shift circuit configured to change the relative phase of the second signal according to a change in frequency.

[0065] 7. The amplifier according to Article 6, wherein the frequency can be continuously varied and the relative phase of the second signal can be continuously varied accordingly.

[0066] 8. The amplifier according to Article 6, wherein the frequency is one of a plurality of discrete predetermined frequencies, and the relative phase of the second signal can be discretely varied accordingly.

[0067] 9. The amplifier according to Article 5 or 6, wherein the second signal path includes an amplitude modulator configured to change the amplitude of the second signal according to a change in frequency.

[0068] 10. The amplifier according to Article 9, wherein the frequency can be continuously varied and the amplitude of the second signal can be continuously varied accordingly.

[0069] 11. The amplifier according to Article 9, wherein the frequency is one of a plurality of discrete predetermined frequencies, and the amplitude of the second signal can be discretely varied accordingly.

[0070] 12. The amplifier according to any one of Clauses 5, 6 or 9, wherein the power stage provided to the second amplifier circuit is capable of varying according to a change in frequency.

[0071] 13. The amplifier according to Clause 12, wherein the frequency can be continuously varied, and the power stage supplied to the second amplifier circuit can be continuously varied accordingly.

[0072] 14. The amplifier according to Clause 12, wherein the frequency is one of a plurality of discrete predetermined frequencies, and the power stage provided to the second amplifier circuit is capable of being discretely varied accordingly.

[0073] 15. The amplifier according to any of the foregoing clauses, wherein each of the first signal path and the second signal path is a corresponding one of the carrier amplifier signal path and the peak amplifier signal path of the inverse Doherty amplifier.

[0074] 16. A wireless telecommunications base station or terminal device, including an amplifier according to Clause 1.

[0075] 17. A method for magnification, comprising:

[0076] A first signal having a frequency and having a phase and amplitude that can vary at that frequency is received by a first amplifier circuit of a first signal path;

[0077] A second amplifier circuit via a second signal path receives a second signal having a frequency, wherein at least one of the relative phase and amplitude of the second signal is fixed at the frequency; and

[0078] Combine the outputs of the first amplifier circuit and the second amplifier circuit.

[0079] 18. A program for controlling a computer to perform the method described in accordance with Clause 17.

[0080] 19. A non-transient storage medium comprising the procedure described in Clause 18.

[0081] Based on the foregoing teachings, numerous modifications and variations of this disclosure are possible. Therefore, it should be understood that this disclosure may be practiced within the scope of the appended claims, and not as specifically described herein.

[0082] As long as the embodiments of this disclosure have been described as being implemented at least in part by a data processing device controlled by software, it should be understood that non-transient machine-readable media carrying such software, such as optical discs, magnetic disks, semiconductor memories, etc., are also considered to represent embodiments of this disclosure.

[0083] It should be understood that, for clarity, the above description has referenced various functional units, circuits, and / or processors in the embodiments. However, it will be apparent that any suitable functional distribution among the various functional units, circuits, and / or processors can be used without affecting the embodiments.

[0084] The described embodiments can be implemented in any suitable form, including hardware, software, firmware, or any combination thereof. The described embodiments can optionally be implemented, at least in part, as computer software running on one or more data processors and / or digital signal processors. Elements and components of any embodiment can be implemented physically, functionally, and logically in any suitable manner. In practice, the functionality can be implemented in a single unit, in multiple units, or as part of other functional units. Therefore, the disclosed embodiments can be implemented in a single unit or can be physically and functionally distributed among different units, circuits, and / or processors.

[0085] Although this disclosure has been described in conjunction with some embodiments, it is not limited to the specific forms set forth herein. Furthermore, while features may be described in conjunction with specific embodiments, those skilled in the art will recognize that the various features of the described embodiments can be combined in any manner suitable for implementing the technology.

Claims

1. An amplifier, comprising: A first signal path includes a first amplifier circuit configured to receive a first signal having a frequency and having a phase and amplitude that can vary at the frequency; The second signal path includes a second amplifier circuit configured to receive a second signal having the frequency, wherein at least one of the relative phase and amplitude of the second signal is fixed at the frequency. The combiner circuit is configured to combine the outputs of the first amplifier circuit and the second amplifier circuit. The first signal and the second signal are obtained by splitting a single input signal; The phase and amplitude of the first input signal at the stated frequency can be varied using a complex nonlinear driving function; The phase and amplitude of the first input signal are variable at the frequency after the individual input signals are split; and After the input signal is shunted using a real nonlinear driving function, only one of the relative phase and amplitude of the second input signal can vary at the stated frequency.

2. The amplifier according to claim 1, wherein: The phase and amplitude of the first input signal are variable at the frequency before the individual input signals are split; The second signal path has a phase delay to fix the relative phase of the second signal at the said frequency; and The second signal path includes a third amplifier circuit, followed by an amplitude limiter to fix the amplitude of the second signal at the frequency.

3. The amplifier according to claim 2, wherein, The second signal path includes a phase shift circuit configured to change the relative phase of the second signal according to the change in frequency.

4. The amplifier according to claim 3, wherein, The frequency can change continuously, and the relative phase of the second signal can change continuously accordingly.

5. The amplifier according to claim 3, wherein, The frequency is one of a plurality of discrete predetermined frequencies, and the relative phase of the second signal can be discretely varied accordingly.

6. The amplifier according to claim 2, wherein, The second signal path includes an amplitude modulator configured to change the amplitude of the second signal according to the change in frequency.

7. The amplifier according to claim 6, wherein, The frequency can change continuously, and the amplitude of the second signal can change continuously accordingly.

8. The amplifier according to claim 6, wherein, The frequency is one of a plurality of discrete predetermined frequencies, and the amplitude of the second signal can be discretely varied accordingly.

9. The amplifier according to claim 2, wherein, The power stage provided to the second amplifier circuit is capable of varying according to the frequency.

10. The amplifier according to claim 9, wherein, The frequency can be continuously varied, and the power level supplied to the second amplifier circuit can be continuously varied accordingly.

11. The amplifier according to claim 9, wherein, The frequency is one of a plurality of discrete predetermined frequencies, and the power level provided to the second amplifier circuit can be discretely varied accordingly.

12. The amplifier according to claim 1, wherein, Each of the first signal path and the second signal path is a corresponding one of the carrier amplifier signal path and the peak amplifier signal path of the inverse Doherty amplifier.

13. A wireless telecommunications base station or terminal device, comprising the amplifier according to claim 1.

14. A method for magnification, comprising: A first signal having a frequency and having a phase and amplitude that can vary at the frequency is received by a first amplifier circuit of a first signal path; A second amplifier circuit of a second signal path receives a second signal having the frequency said above, wherein at least one of the relative phase and amplitude of the second signal is fixed at said frequency; and Combining the outputs of the first amplifier circuit and the second amplifier circuit, The first signal and the second signal are obtained by splitting a single input signal; The phase and amplitude of the first input signal at the stated frequency can be varied using a complex nonlinear driving function; The phase and amplitude of the first input signal are variable at the frequency after the individual input signals are split; and After the input signal is shunted using a real nonlinear driving function, only one of the relative phase and amplitude of the second input signal can vary at the stated frequency.

15. A non-transient storage medium comprising a program for controlling a computer to perform the method according to claim 14.

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