Transmitting apparatus and output power control method

Abstract

The application discloses a transmitting device and an output power control method. The transmitting device comprises a control module, a digital-to-analog converter, a low-pass filter module, a voltage-current conversion module and a power mixing module. The control module is connected with the low-pass filter module, the voltage-current conversion module and the power mixing module. The low-pass filter module is connected with the digital-to-analog converter and the voltage-current conversion module. The voltage-current conversion module is connected with the power mixing module. The power mixing module comprises a plurality of mixing units connected with the voltage-current conversion module. The control module controls the gain of the low-pass filter module to realize the optimized control of the power consumption of the transmitting device by controlling the gain. Meanwhile, the application alleviates the driving requirement of the front-stage low-pass filter module, avoids the low-pass filter module from becoming the bottleneck of the linearity of the transmitting device, and thus realizes the high linearity and low power consumption of the transmitting device.

Description

Technical Field

[0001] This invention relates to the field of radio frequency communication technology, and in particular to a transmitting device and an output power control method. Background Technology

[0002] With the development of various applications such as satellite communication and terrestrial communication, the transmission of terminal equipment needs to adapt to different transmission power requirements. When communicating with distant satellites, greater output power is required to improve communication quality; while in some short-range communication applications, it is often necessary to reduce transmission power and equipment power consumption to improve equipment standby time.

[0003] CMOS technology has become the mainstream process for transmitters due to its advantages such as low power consumption and high integration. However, it faces challenges in outputting high power and achieving high reliability at low voltages. For transmitters with voltage mixer structures, to increase the transmit output power, one or two stages of RF driver amplifiers need to be added after the mixer to raise the transmitter output power to the 5 dBm to 10 dBm level. However, this requires a higher supply voltage, and the added RF driver amplifier consumes a significant amount of power while operating at high frequencies.

[0004] See Figure 1 As shown, the current-mode power mixer architecture in the prior art can operate at a lower supply voltage. However, since the low-pass filter (LPF) needs to provide current output, it places high demands on the driving capability of the low-pass filter, which will increase the current consumption (power consumption) of the low-pass filter and may even affect the frequency characteristics of the low-pass filter, such as bandwidth, phase margin, and group delay.

[0005] Therefore, when performing output power control, existing transmitters are prone to problems such as low linearity and high power consumption due to insufficient driving capability of the low-pass filter. Summary of the Invention

[0006] In order to overcome the shortcomings of the prior art, the present invention aims to provide a transmitting device and an output power control method, which alleviates the driving requirements of the front-end low-pass filter module, avoids the low-pass filter module becoming a bottleneck restricting the linearity of the transmitting device, and thus achieves high linearity and low power consumption of the transmitting device.

[0007] To solve the above problems, the present invention is implemented according to the following solution:

[0008] A transmitting device is provided, comprising: a control module, a digital-to-analog converter, a low-pass filter module, a voltage-to-current converter module, and a power mixer module; the control module is connected to the low-pass filter module, the voltage-to-current converter module, and the power mixer module; the low-pass filter module is connected to the digital-to-analog converter and the voltage-to-current converter module; and the voltage-to-current converter module is connected to the power mixer module.

[0009] The power mixing module includes multiple mixing units connected to the voltage-to-current conversion module;

[0010] The digital-to-analog converter converts the digital input signal into an analog voltage signal and sends it to the low-pass filter module; the control module generates control signals and switching signals.

[0011] The low-pass filter module filters the analog voltage signal according to the control signal to obtain a differential voltage signal sent to the voltage-to-current conversion module. The voltage-to-current conversion module generates a bias current according to the control signal and converts the differential voltage signal into a current signal sent to the power mixer module according to the bias current.

[0012] The power mixing module controls the number of mixing units to be turned on according to the switching signal, and controls the output power of the current signal according to the number of mixing units to be turned on.

[0013] Compared with the prior art, the beneficial effects of the transmitting device of the present invention are as follows: By controlling the voltage-to-current conversion module to dynamically generate bias current through the control module, the internal current distribution can be flexibly adjusted according to the differential voltage signal, thereby reducing the current extraction from the differential voltage signal and giving the input terminal of the voltage-to-current conversion module a high impedance characteristic. This high impedance characteristic makes the current obtained by the front-stage low-pass filter module extremely small, greatly reducing its driving pressure. The reduction of driving pressure can avoid the low-pass filter module from generating nonlinear distortion due to excessive driving load, thereby preventing it from becoming a linear bottleneck of the transmitting device, and finally achieving high linearity and low power consumption of the transmitting device.

[0014] Optionally, the low-pass filter module includes a control unit, a second-order active filter, and a first-order passive filter; the control unit includes a first resistor and a second resistor.

[0015] The first resistor is connected to the positive input terminal of the digital-to-analog converter and the second-order active filter; the second resistor is connected to the negative input terminal of the digital-to-analog converter and the second-order active filter; the first-order passive filter is connected to the second-order active filter and the voltage-to-current conversion module; the control module is connected to the first resistor and the second resistor.

[0016] Optionally, the second-order active filter includes a first filtering unit and a second filtering unit, wherein the first filtering unit includes a first filter, a first capacitor, a second capacitor, a third resistor, and a fourth resistor;

[0017] The positive input terminal of the first filter is connected to the first resistor, the positive input terminal of the first filter is connected to the negative output terminal of the first filter through the first capacitor, the negative input terminal of the first filter is connected to the second resistor, and the negative input terminal of the first filter is connected to the positive output terminal of the first filter through the second capacitor.

[0018] The second filter unit is connected to the third resistor and the fourth resistor.

[0019] Optionally, the second filtering unit includes a second filter, a third capacitor, a fourth capacitor, a fifth resistor, a sixth resistor, a seventh resistor, and an eighth resistor;

[0020] The third resistor is connected to the positive input terminal of the second filter, and the fourth resistor is connected to the negative input terminal of the second filter.

[0021] The third capacitor and the fifth resistor are connected in parallel to form the first branch, and the fourth capacitor and the sixth resistor are connected in parallel to form the second branch. The positive input terminal of the second filter is connected to the negative output terminal of the second filter through the first branch, and the negative input terminal of the second filter is connected to the positive output terminal of the second filter through the second branch.

[0022] The positive input terminal of the first filter is connected to the negative output terminal of the second filter through the seventh resistor, and the negative input terminal of the first filter is connected to the positive output terminal of the second filter through the eighth resistor; the first-order passive filter is connected to the positive output terminal and the negative output terminal of the second filter.

[0023] Optionally, the first-order passive filter includes a ninth resistor, a tenth resistor, a fifth capacitor, and a sixth capacitor;

[0024] The fifth capacitor and the sixth capacitor are connected in parallel to form the third branch. The negative output terminal of the second filter is connected to the positive output terminal of the second filter in sequence through the ninth resistor, the third branch, and the tenth resistor. The third branch is connected to the voltage-to-current conversion module.

[0025] Optionally, the voltage-to-current conversion module includes two identical conversion circuits and a seventh capacitor; the conversion circuit includes an operational amplifier, a first MOSFET, an eleventh resistor, a bias current source, a twelfth resistor, and an eighth capacitor;

[0026] The low-pass filter module is connected to the negative input terminal of the operational amplifier. The positive input terminal of the operational amplifier is connected to the drain of the first MOS transistor, the eleventh resistor, and the bias current source. The output terminal of the operational amplifier is connected to the gate of the first MOS transistor. The output terminal of the operational amplifier is grounded through the twelfth resistor and the eighth capacitor in sequence. The twelfth resistor is connected to the power mixer module. The source of the first MOS transistor is grounded. The eleventh resistor is grounded through the seventh capacitor. The bias current source is connected to the control module.

[0027] Optionally, the power mixer module further includes a balun unit, the mixer unit is connected to the balun unit, and the balun unit is used to convert the output signal of the mixer unit from a dual-ended output to a single-ended output.

[0028] Optionally, the mixing unit includes a second MOS transistor, a third MOS transistor, a first switching unit, a second switching unit, and two mixing circuits with identical structures;

[0029] The voltage-to-current conversion module is connected to the mixer circuit, the mixer circuit is connected to the source of the second MOSFET and the source of the third MOSFET, the first switching unit is connected to the gate of the second MOSFET, and the second switching unit is connected to the gate of the third MOSFET; the balun unit is connected to the drain of the second MOSFET and the drain of the third MOSFET.

[0030] The control module is connected to the first switch unit and the second switch unit.

[0031] Optionally, the mixer circuit includes a fourth MOSFET, a fifth MOSFET, a sixth MOSFET, and a third switching unit;

[0032] The third switching unit is connected to the voltage-to-current conversion module and the gate of the fourth MOS transistor. The drain of the fourth MOS transistor is connected to the source of the fifth MOS transistor and the source of the sixth MOS transistor. The drain of the fifth MOS transistor is connected to the source of the second MOS transistor. The drain of the sixth MOS transistor is connected to the source of the third MOS transistor.

[0033] The control module is connected to the third switch unit.

[0034] An output power control method is also provided for controlling the output power of the aforementioned transmitting device, comprising:

[0035] The digital-to-analog converter converts the digital input signal into an analog voltage signal and sends it to the low-pass filter module. The control module generates control signals and switching signals. The control signals are used to control the resistance values ​​of the first resistor and the second resistor in the low-pass filter module, and also to control the bias current source of the voltage-to-current conversion module to generate bias current. The switching signals are used to control the first switching unit, the second switching unit, and the third switching unit in the mixer unit to turn on or off.

[0036] The low-pass filter module determines the gain based on the resistance values ​​of the first resistor and the second resistor, and filters the analog voltage signal according to the gain to obtain a differential voltage signal sent to the voltage-to-current conversion module.

[0037] The voltage-to-current conversion module converts the differential voltage signal into a current signal that is sent to the power mixer module based on the bias current.

[0038] The power mixing module determines the number of mixing units to be turned on based on the switching signal, and controls the output power of the current signal based on the number of mixing units to be turned on. Attached Figure Description

[0039] Figure 1 This is a diagram of a current-mode based power mixer architecture in the prior art;

[0040] Figure 2 This is an overall structural block diagram of the launching device of the present invention;

[0041] Figure 3 This is a circuit diagram of the low-pass filter module of the present invention;

[0042] Figure 4 This is a circuit diagram of the voltage-to-current conversion module of the present invention;

[0043] Figure 5 This is a circuit diagram of a single mixer unit of the present invention;

[0044] Figure 6 The bias current I of the voltage-to-current conversion module of this invention dc A table showing the relationship between the decrease of the resistor R1 in the low-pass filter module as the resistor R1 increases;

[0045] The attached diagram shows the following reference numerals: 1. Control module; 2. Digital-to-analog converter; 3. Low-pass filter module; 301. Control unit to be controlled; 302. Second-order active filter; 3021. First filter unit; 3022. Second filter unit; 303. First-order passive filter; 4. Voltage-to-current conversion module; 401. Conversion circuit; 5. Power mixer module; 501. Mixer unit; 5011. First switching unit; 5012. Second switching unit; 5013. Mixer circuit; 502. Balun unit. Detailed Implementation

[0046] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0047] In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims. In the description of this application, it should be understood that the terms "first," "second," "third," etc., are used only to distinguish similar objects and are not necessarily used to describe a specific order or sequence, nor should they be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0048] See Figure 2-5 As shown, a transmitting device includes: a control module 1, a digital-to-analog converter 2, a low-pass filter module 3, a voltage-to-current converter module 4, and a power mixer module 5; the control module 1 is connected to the low-pass filter module 3, the voltage-to-current converter module 4, and the power mixer module 5; the low-pass filter module 3 is connected to the digital-to-analog converter 2 and the voltage-to-current converter module 4; the voltage-to-current converter module 4 is connected to the power mixer module 5; wherein, the power mixer module 5 includes a plurality of mixer units 501 connected to the voltage-to-current converter module 4.

[0049] In one embodiment of the present invention, the digital-to-analog converter 2 converts the digital input signal into an analog voltage signal V. i The signal is then sent to the low-pass filter module 3. The control module 1 generates control signals that are sent to the low-pass filter module 3 and the voltage-to-current conversion module 4, and a switching signal that is sent to the power mixer module 5. The low-pass filter module 3 adjusts the analog voltage signal V according to the control signals. i After filtering, the differential voltage signal V is obtained and sent to the voltage-to-current conversion module 4. o Specifically, the low-pass filter module 3 determines the filter to be used for the analog voltage signal V based on the control signal.i The gain of the processing; the voltage-to-current conversion module 4 generates a bias current I based on the control signal. dc According to the bias current I dc For differential voltage signal V o The signal is converted into a current signal and sent to the power mixer module 5. Finally, the power mixer module 5 controls the number of mixer units 501 that are turned on according to the switch signal, and controls the output power of the current signal according to the number of mixer units 501 that are turned on.

[0050] In one embodiment of the present invention, the low-pass filter module 3 includes a control unit 301, a second-order active filter 302, and a first-order passive filter 303; wherein, the control unit 301 includes a first resistor R1 and a second resistor R2; the first resistor R1 is connected to the positive input terminal of the digital-to-analog converter 2 and the second-order active filter 302, and the second resistor R2 is connected to the negative input terminal of the digital-to-analog converter 2 and the second-order active filter 302; the first-order passive filter 303 is connected to the second-order active filter 302 and the voltage-to-current conversion module 4; the control module 1 is connected to the first resistor, R1, and the second resistor R2.

[0051] In one embodiment of the present invention, the second-order active filter 302 includes a first filter unit 3021 and a second filter unit 3022. The first filter unit 3021 includes a first filter F1, a first capacitor C1, a second capacitor C2, a third resistor R3, and a fourth resistor R4. The positive input terminal of the first filter F1 is connected to the first resistor R1, the positive input terminal of the first filter F1 is connected to the negative output terminal of the first filter F1 through the first capacitor C1, the negative input terminal of the first filter F1 is connected to the second resistor R2, and the negative input terminal of the first filter F1 is connected to the positive output terminal of the first filter F1 through the second capacitor C2. The second filter unit 3022 is connected to the third resistor R3 and the fourth resistor R4.

[0052] In one embodiment of the present invention, the second filtering unit 3022 includes a second filter F2, a third capacitor C3, a fourth capacitor C4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, and an eighth resistor R8; the third resistor R3 is connected to the positive input terminal of the second filter F2, and the fourth resistor R4 is connected to the negative input terminal of the second filter F2; the third capacitor C3 and the fifth resistor R5 are connected in parallel to form a first branch, and the fourth capacitor C4 and the sixth resistor R6 are connected in parallel to form a second branch; the positive input terminal of the second filter F2 is connected to the negative output terminal of the second filter F2 through the first branch, and the negative input terminal of the second filter F2 is connected to the positive output terminal of the second filter F2 through the second branch; the positive input terminal of the first filter F1 is connected to the negative output terminal of the second filter F2 through the seventh resistor R7, and the negative input terminal of the first filter F1 is connected to the positive output terminal of the second filter F2 through the eighth resistor R8; the first-order passive filter 303 is connected to the positive output terminal and the negative output terminal of the second filter F2.

[0053] In one embodiment of the present invention, the first-order passive filter 303 includes a ninth resistor R9 and a tenth resistor R 10 The fifth capacitor C5 and the sixth capacitor C6 are connected in parallel to form the third branch. The negative output terminal of the second filter F2 is connected sequentially through the ninth resistor R9, the third branch, and the tenth resistor R. 10 Connect the positive output terminal of the second filter F2; the third branch is connected to the voltage-to-current conversion module 4.

[0054] In this invention, the second-order active filter unit of the low-pass filter module 3 is a Tow-Thomas filter, and the transfer function of the low-pass filter module 3 is:

[0055]

[0056] The bandwidth of the second-order active filter unit is:

[0057]

[0058] The bandwidth of the first-order passive filter unit is:

[0059]

[0060] For the useful signal within the low-pass filter module 3, it is divided into positive terminal signal and negative terminal signal. The gain of the positive terminal signal is approximately R7 / R1, and the gain of the negative terminal signal is approximately R8 / R2. Through the connection relationship between the control module 1 and the first resistor R1 and the second resistor R2, the control signal generated by the control module 1 is sent to the first resistor R1 and the second resistor R2. By adjusting the resistance values ​​of the first resistor R1 and the second resistor R2, precise control of its gain can be achieved without affecting the bandwidth of the low-pass filter module 3.

[0061] In one embodiment of the present invention, the resistance values ​​of the first resistor R1 and the second resistor R2 are controlled by the control module 1, so that the gain of the low-pass filter module 3 is 0dB to -6dB, with a step of 0.4dB.

[0062] In one embodiment of the present invention, the voltage-to-current conversion module 4 includes two identical conversion circuits 401 and a seventh capacitor; the conversion circuit 401 includes an operational amplifier OP, a first MOSFET M1, and an eleventh resistor R. 11 Bias current source, twelfth resistor R 12 And the eighth capacitor C8; the low-pass filter module 3 is connected to the negative input terminal of the operational amplifier OP, and the positive input terminal of the operational amplifier OP is connected to the drain of the first MOSFET M1 and the eleventh resistor R. 11 The bias current source is connected, and the output terminal of the operational amplifier OP is connected to the gate of the first MOSFET M1. The output terminal of the operational amplifier OP is connected in sequence through the twelfth resistor R. 12 The eighth capacitor C8 is grounded, and the twelfth resistor R 12 Connect power mixer module 5, the source of the first MOSFET M1 is grounded, and the eleventh resistor R 11 The seventh capacitor C7 is grounded, and the bias current source is connected to the control module 1.

[0063] In one embodiment of the present invention, the analog voltage signal V output by the low-pass filter module 3 o Since the signal is divided into a positive terminal and a negative terminal, the two identical conversion circuits 401 are used to process the positive terminal signal and the negative terminal signal respectively, and the processing is the same.

[0064] This invention uses control signals generated by control module 1 to control a bias current source to dynamically generate bias currents I of different magnitudes. dc The voltage-to-current conversion module 4 uses the dynamically generated bias current I... dc The differential voltage signal V o Converting it to a current signal reduces the influence of the transconductance nonlinearity of the power mixer module 5, improving the linearity and output power of the transmitting device; and its equivalent input impedance R inThe parasitic capacitance of the operational amplifier (OP) has almost no effect on the low-pass filter module 3 in the preceding stage, which reduces the current drive capability of the low-pass filter module 3 and lowers its power consumption.

[0065] To improve the suppression of harmonic distortion and far-end noise in the voltage-to-current conversion module 4, the eleventh resistor R in the two conversion circuits 401 is... 11 A seventh capacitor C7 connected to ground is added in the middle to filter high-frequency common-mode noise. The input of the conversion circuit 401 is the differential input pair of the operational amplifier OP. The input impedance Rin of the operational amplifier OP is high impedance, thereby alleviating the driving requirements of the front-stage low-pass filter module 3.

[0066] For analog voltage signal V o positive terminal signal V inp Analysis is performed when the input voltage V inp When the gain is increased, since the gain of the operational amplifier OP is G m R0, the output voltage of operational amplifier OP is V GP The transconductance of the first MOSFET M1 decreases to g. m The current signal I generated at this time inp Decrease, voltage signal V XP The flow increases and flows through the eleventh resistor R. 11 Current I ac(t) Increase the input differential voltage (V) of the operational amplifier OP. XP With V inp As the difference decreases, the negative feedback loop reaches equilibrium again; for the operational amplifier OP, the following mathematical relationship exists between its positive and negative input parameters:

[0067]

[0068]

[0069] For operational amplifiers (OPs), there exists The mathematical relationship, thus Therefore, the voltage-current conversion relationship of the voltage-current conversion module 4 of the present invention is as follows:

[0070]

[0071] in, For the flow through the eleventh resistor R 11 The current signal, R 11 This is the resistance value of the eleventh resistor. This is the positive terminal signal of the analog voltage signal. This is the negative terminal signal of the analog voltage signal.

[0072] If the power supply voltage of low-pass filter module 3 is V DDL Therefore, the maximum AC current is the current when the low-pass filter module 3 outputs at full swing, i.e., I. ac（max） =V DDL / (2R 11 To ensure that the low-pass filter module 3 can operate at full swing, the DC current of the first MOSFET M1 must be greater than or equal to the power supply voltage V. DDL / (2R1) or V DDL / (2R2), based on the width-to-length ratio of the fourth MOSFET M4 to the first MOSFET M1 in the mirror current source being N:1, we can obtain:

[0073]

[0074]

[0075] AC current signal I output to power mixer module 5 out,ac for:

[0076]

[0077] The input AC signal swing of voltage-to-current conversion module 4 is V. in The sum of the DC currents of the two differential channels of the power mixer module is 2N*I. dc .

[0078] In one embodiment of the present invention, the power mixing module 5 further includes a balun unit 502, which is connected to the mixing unit 501. The balun unit 502 is used to convert the output signal of the mixing unit 501 from a dual-ended output to a single-ended output. The power mixing module 5 also includes a ninth capacitor C9, which is connected to the mixing unit 501 to filter the output signal of the mixing unit 501 before converting it to a single-ended output via the balun unit 502, thereby improving the accuracy of the output signal of the transmitting device. The balun unit 502 and the ninth capacitor C9 form an output load, converting the current signal output by the mixing unit 501 into a voltage signal.

[0079] In one embodiment of the present invention, the mixing unit 501 includes a second MOSFET M2, a third MOSFET M3, a first switching unit 5011, a second switching unit 5012, and two identical mixing circuits 5013; the voltage-to-current conversion module 4 is connected to the mixing circuit 5013, the mixing circuit 5013 is connected to the source of the second MOSFET M2 and the source of the third MOSFET M3, the first switching unit 5011 is connected to the gate of the second MOSFET M2, and the second switching unit 5012 is connected to the gate of the third MOSFET M3; the balun unit 502 is connected to the drain of the second MOSFET M2 and the drain of the third MOSFET M3; the control module 1 is connected to the first switching unit 5011 and the second switching unit 5012. The first switching unit 5011 includes a bias voltage V. BH First switch S1, second switch S2, the gate and bias voltage V of the first switch S1 and the second MOSFET M2 BH The second switch S2 is connected to the gate and ground of the second MOSFET M2; the second switching unit 5012 includes a bias voltage V. BH The third switch S3 and the fourth switch S4, the gate and bias voltage V of the third switch S3 and the third MOSFET M3 BH The fourth switch S4 is connected to the gate and ground of the third MOSFET M3.

[0080] In one embodiment of the present invention, the mixer circuit 5013 includes a fourth MOSFET M4, a fifth MOSFET M5, a sixth MOSFET M6, and a third switching unit. The third switching unit is connected to the voltage-to-current conversion module 4 and the gate of the fourth MOSFET M4. The drain of the fourth MOSFET M4 is connected to the source of the fifth MOSFET M5 and the source of the sixth MOSFET M6. The drain of the fifth MOSFET M5 is connected to the source of the second MOSFET M2, and the drain of the sixth MOSFET M6 is connected to the source of the third MOSFET M3. The control module 1 is connected to the third switching unit. The third switching unit includes a fifth switch S5 and a sixth switch S6. The fifth switch S5 is connected to the gate of the fourth MOSFET M4 and the voltage-to-current conversion module 4, and the sixth switch S6 is connected to the gate of the fourth MOSFET M4 and ground.

[0081] In this invention, the current signal output by the voltage-to-current conversion module 4 is divided into a positive terminal signal and a negative terminal signal. Therefore, the two mixer circuits 5013 with the same structure are used to process the positive terminal signal and the negative terminal signal respectively, and the processing process is the same.

[0082] This invention controls the switching state of the mixer unit 501 by controlling the switching states of the first switch S1, the second switch S2, the third switch S3, the fourth switch S4, the fifth switch S5, and the sixth switch S6. Taking the positive terminal signal as an example, the control process of the mixer unit 501 is explained as follows: When the switch signal generated by the control module 1 controls the first switch S1, the third switch S3, and the fifth switch S5 to be turned on, and the second switch S2, the fourth switch S4, and the sixth switch S6 to be turned off, the gates of the second MOSFET M2 and the third MOSFET M3 are connected to the bias voltage, and the gate of the fourth MOSFET M4 is connected to the current signal output by the voltage-to-current conversion module 4. At this time, the mixer unit 501 is turned on. When the switch signal generated by the control module 1 controls the first switch S1, the third switch S3, and the fifth switch S5 to be turned off, and the second switch S2, the fourth switch S4, and the sixth switch S6 to be turned on, the gates of the second MOSFET M2, the third MOSFET M3, and the fourth MOSFET M4 are all grounded. At this time, the mixer unit 501 is turned off.

[0083] In one embodiment of the present invention, the first MOSFET M1 in the voltage-to-current conversion module 4 and the fourth MOSFET M4 in the power mixer module 5 are mirror current sources, and their width-to-length ratio is N:1 (M4:M1); a twelfth resistor R is connected in series between the mirror current sources (M4 and M1). 12 An eighth capacitor C8 is added to ground to form a pole p1, which can be set outside the third harmonic of the signal to suppress noise generated by the mirror current source.

[0084] In this invention, the fourth MOSFET M4 of the power mixer module 5 is in a multiple relationship with the first MOSFET M1 of the voltage-to-current conversion module 4, realizing a linear voltage-to-current conversion and current amplification process. The mirrored current signal is amplified and mixed, and the mixed RF current signal passes through the output load R composed of the balun unit 502 and the ninth capacitor C9. L This generates an RF voltage signal that can drive external devices, thus realizing the function of "upconversion + drive amplifier".

[0085] Assuming the power mixer module 5 includes M independently controllable mixer units 501, the output power and power consumption are controlled by controlling the number of mixer units 501 that are turned on. The input current (AC current signal) of each mixer unit is... The current signal output by the mixer unit 501 is 2M*N*I. dc Its output power is:

[0086]

[0087] When the number of mixing units 501 is 64, the gain of the power mixing module 5 is controlled by turning on and off the 64 identical mixing units 501. By configuring the number of mixing units 501 on, M', to be 64, 32, 16, 8, 4, 2, or 1, maximum gain attenuation of 0 dB, -6 dB, -12 dB, -18 dB, -24 dB, -32 dB, and -36 dB can be achieved respectively. For example, when M=64, the output power reaches its maximum value P. out(M=64) =P out,max When M=32, the output power is: P out(M=32) = P out,max / 4, convert it to a logarithmic relation:

[0088] 10*log(P out(M=32) )=10*log(P out,max / 4)=10*log(P out,max )-6=10*log(P out(M=64) )-6

[0089] That is, P out(M=32) The output power is P out(M=64) The attenuation is 6 dB, and so on. Combining the 6 dB gain attenuation control range of the power mixer module 5 and the 0.4 dB gain attenuation step of the low-pass filter module 3, the transmitter achieves a gain control range of 42 dB in 0.4 dB steps.

[0090] An output power control method of the present invention is used to control the output power of the above-mentioned transmitting device, comprising:

[0091] The digital-to-analog converter 2 converts the digital input signal into an analog voltage signal and sends it to the low-pass filter module 3. The control module 1 generates control signals and switching signals. The control signals are used to control the resistance values ​​of the first resistor and the second resistor in the low-pass filter module 3, and also to control the bias current source of the voltage-to-current conversion module 4 to generate bias current. The switching signals are used to control the first switching unit 5011, the second switching unit 5012, and the third switching unit in the mixer unit 501 to turn on or off.

[0092] The low-pass filter module 3 determines the gain based on the resistance values ​​of the first resistor and the second resistor, and filters the analog voltage signal according to the gain to obtain the differential voltage signal sent to the voltage-to-current conversion module 4.

[0093] The voltage-to-current conversion module 4 converts the differential voltage signal into a current signal that is sent to the power mixer module 5 based on the bias current.

[0094] The power mixing module 5 determines the number of mixing units 501 to be turned on based on the switching signal, and controls the output power of the current signal based on the number of mixing units 501 to be turned on.

[0095] Specifically, when maximum power output is required, control module 1 generates a switching signal to control all mixer units 501 to turn on, and generates a control signal to ensure that the bias current dynamically generated by the bias current source is greater than or equal to V. DDL / (2R 11 ), where V DDL The power supply voltage of the low-pass filter module 3 is used to make the current signal M*I output by the voltage-to-current conversion module 4. out To avoid current limiting causing output power saturation and to increase maximum output power.

[0096] When maximum power output is not required, there are two ways to achieve attenuation of gain and reduction of power consumption:

[0097] 1) The first method

[0098] Based on the above formula for calculating output power, by modifying the number M of the mixing unit 501 that is turned on, a large step attenuation is achieved, thereby reducing the output power P. out This reduces the output current of multiple mixer units 501 by 2M*N*I. dc This reduces power consumption.

[0099] 2) Based on the gain R7 / R1 or R8 / R2 of the low-pass filter module 3, by modifying the resistance values ​​of R1 and R2, the output amplitude of the low-pass filter module 3 is reduced, which in turn reduces the input amplitude of the voltage-to-current conversion module 4. For example, when the low-pass filter module 3 has a gain of 0dB, the maximum output amplitude V is achieved when R7=R1 or R8=R2. FS That is, the input V of voltage-to-current conversion module 4 in (V inp / V inn )=V FS Maximum amplitude V FS This represents the full-amplitude input voltage. When R7 or R8 remains unchanged, and the resistance value of R1 is adjusted to 1.047R7, and the resistance value of R2 is adjusted to 1.047R8, the voltage gain of the low-pass filter module 3 decreases to R7 / R1=R8 / R2=R7 / (1.047R7)=R8 / (1.047R8)=0.955, which can be converted to a logarithmic relationship as follows:

[0100] 20*log(0.955)=-0.4 dB

[0101] Its output amplitude is 0.955*V FS That is, the input voltage signal V of voltage-to-current conversion module 4 in (Vinp / V inn )=0.955*V FS Based on the above formula for calculating output power, the voltage-to-current conversion module 4 outputs power at its maximum amplitude V. FS When used as input:

[0102]

[0103] The input amplitude of voltage-to-current conversion module 4 is V in (V inp / V inn )=0.955*V FS hour,

[0104]

[0105] The logarithmic difference between the two is:

[0106]

[0107] This can reduce the output power by 0.4dB, achieving small step gain control.

[0108] With the analog voltage signal V output by low-pass filter module 3 o (V inp / V inn As the voltage decreases, the signal amplitude is no longer at full swing, and the DC current of the first MOSFET M1 in voltage-to-current conversion module 4 can be less than V. DDL / (2R1), therefore, by controlling the generation of the bias current source to dynamically generate bias current I, the bias current I is reduced accordingly. dc The control signal is used to proportionally reduce the DC current 2M*N*I output by multiple mixer units 501. dc This achieves reduced power consumption. See [link to example]. Figure 6 As shown, the bias current I of voltage-to-current conversion module 4 is illustrated. dc The relationship is that the resistance R1 of the low-pass filter module 3 decreases as the resistance R2 increases.

[0109] By combining the two control methods mentioned above, the control module 1 achieves large dynamic range and fine-step output power control by combining large step gain control and small step gain control, thereby reducing the power consumption of the transmitter while reducing the output power.

[0110] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A launching device, characterized in that, include: Control module, digital-to-analog converter, low-pass filter module, voltage-to-current converter module and power mixer module; The control module is connected to the low-pass filter module, the voltage-to-current conversion module, and the power mixer module; the low-pass filter module is connected to the digital-to-analog converter and the voltage-to-current conversion module; the voltage-to-current conversion module is connected to the power mixer module. The power mixing module includes multiple mixing units connected to the voltage-to-current conversion module; The digital-to-analog converter converts the digital input signal into an analog voltage signal and sends it to the low-pass filter module; the control module generates control signals and switching signals. The low-pass filter module filters the analog voltage signal according to the control signal to obtain a differential voltage signal sent to the voltage-to-current conversion module. The voltage-to-current conversion module generates a bias current according to the control signal and converts the differential voltage signal into a current signal sent to the power mixer module according to the bias current. The power mixing module controls the number of mixing units to be turned on according to the switching signal, and controls the output power of the current signal according to the number of mixing units to be turned on.

2. The launching device according to claim 1, characterized in that, The low-pass filter module includes a control unit, a second-order active filter, and a first-order passive filter; the control unit includes a first resistor and a second resistor. The first resistor is connected to the positive input terminal of the digital-to-analog converter and the second-order active filter; the second resistor is connected to the negative input terminal of the digital-to-analog converter and the second-order active filter; the first-order passive filter is connected to the second-order active filter and the voltage-to-current conversion module; the control module is connected to the first resistor and the second resistor.

3. The launching device according to claim 2, characterized in that, The second-order active filter includes a first filter unit and a second filter unit. The first filter unit includes a first filter, a first capacitor, a second capacitor, a third resistor, and a fourth resistor. The positive input terminal of the first filter is connected to the first resistor, the positive input terminal of the first filter is connected to the negative output terminal of the first filter through the first capacitor, the negative input terminal of the first filter is connected to the second resistor, and the negative input terminal of the first filter is connected to the positive output terminal of the first filter through the second capacitor. The second filter unit is connected to the third resistor and the fourth resistor.

4. A launching device according to claim 3, characterized in that, The second filtering unit includes a second filter, a third capacitor, a fourth capacitor, a fifth resistor, a sixth resistor, a seventh resistor, and an eighth resistor; The third resistor is connected to the positive input terminal of the second filter, and the fourth resistor is connected to the negative input terminal of the second filter. The third capacitor and the fifth resistor are connected in parallel to form the first branch, and the fourth capacitor and the sixth resistor are connected in parallel to form the second branch. The positive input terminal of the second filter is connected to the negative output terminal of the second filter through the first branch, and the negative input terminal of the second filter is connected to the positive output terminal of the second filter through the second branch. The positive input terminal of the first filter is connected to the negative output terminal of the second filter through the seventh resistor, and the negative input terminal of the first filter is connected to the positive output terminal of the second filter through the eighth resistor; the first-order passive filter is connected to the positive output terminal and the negative output terminal of the second filter.

5. A launching device according to claim 4, characterized in that, The first-order passive filter includes a ninth resistor, a tenth resistor, a fifth capacitor, and a sixth capacitor; The fifth capacitor and the sixth capacitor are connected in parallel to form the third branch. The negative output terminal of the second filter is connected to the positive output terminal of the second filter in sequence through the ninth resistor, the third branch, and the tenth resistor. The third branch is connected to the voltage-to-current conversion module.

6. A launching device according to claim 1, characterized in that, The voltage-to-current conversion module includes two identical conversion circuits and a seventh capacitor; the conversion circuit includes an operational amplifier, a first MOSFET, an eleventh resistor, a bias current source, a twelfth resistor, and an eighth capacitor; The low-pass filter module is connected to the negative input terminal of the operational amplifier. The positive input terminal of the operational amplifier is connected to the drain of the first MOS transistor, the eleventh resistor, and the bias current source. The output terminal of the operational amplifier is connected to the gate of the first MOS transistor. The output terminal of the operational amplifier is grounded through the twelfth resistor and the eighth capacitor in sequence. The twelfth resistor is connected to the power mixer module. The source of the first MOS transistor is grounded. The eleventh resistor is grounded through the seventh capacitor. The bias current source is connected to the control module.

7. A launching device according to claim 1, characterized in that, The power mixing module also includes a balun unit, which is connected to the mixing unit. The balun unit is used to convert the output signal of the mixing unit from a dual-ended output to a single-ended output.

8. A launching device according to claim 7, characterized in that, The mixing unit includes a second MOS transistor, a third MOS transistor, a first switching unit, a second switching unit, and two mixing circuits with identical structures; The voltage-to-current conversion module is connected to the mixer circuit, the mixer circuit is connected to the source of the second MOSFET and the source of the third MOSFET, the first switching unit is connected to the gate of the second MOSFET, and the second switching unit is connected to the gate of the third MOSFET; the balun unit is connected to the drain of the second MOSFET and the drain of the third MOSFET. The control module is connected to the first switch unit and the second switch unit.

9. A launching device according to claim 8, characterized in that, The mixer circuit includes a fourth MOSFET, a fifth MOSFET, a sixth MOSFET, and a third switching unit; The third switching unit is connected to the voltage-to-current conversion module and the gate of the fourth MOS transistor. The drain of the fourth MOS transistor is connected to the source of the fifth MOS transistor and the source of the sixth MOS transistor. The drain of the fifth MOS transistor is connected to the source of the second MOS transistor. The drain of the sixth MOS transistor is connected to the source of the third MOS transistor. The control module is connected to the third switch unit.

10. An output power control method for controlling the output power of a transmitting device as described in claim 9, characterized in that, include: The digital-to-analog converter converts the digital input signal into an analog voltage signal and sends it to the low-pass filter module. The control module generates control signals and switching signals. The control signal is used to control the resistance values ​​of the first resistor and the second resistor in the low-pass filter module, and also to control the bias current source of the voltage-to-current conversion module to generate bias current; the switch signal is used to control the first switch unit, the second switch unit and the third switch unit in the mixer unit to turn on or off. The low-pass filter module determines the gain based on the resistance values ​​of the first resistor and the second resistor, and filters the analog voltage signal according to the gain to obtain a differential voltage signal sent to the voltage-to-current conversion module. The voltage-to-current conversion module converts the differential voltage signal into a current signal that is sent to the power mixer module based on the bias current. The power mixing module determines the number of mixing units to be turned on based on the switching signal, and controls the output power of the current signal based on the number of mixing units to be turned on.

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