Ku wave band broadband high-efficiency power amplifier with adjustable final-stage impedance
Patent Information
- Application Number
- CN202423101435.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-16
- Publication Date
- 2025-11-07
- Estimated Expiration
- 2034-12-16
AI Technical Summary
Existing Ku-band power amplifiers suffer from efficiency and power degradation with frequency changes, leading to increased system power supply burden. Furthermore, traditional methods offer limited improvement and require a large area.
By connecting field-effect transistors in parallel in the matching network and controlling their gate voltage to change the capacitance value, the final stage impedance can be adjusted to adapt to different frequency bands. Combining two field-effect transistors of the same size in parallel reduces the resistance value and controls the power supply voltage to be consistent with the power amplifier.
It improves the output power and efficiency of broadband power amplifiers, reduces system power requirements, has a simple structure, does not require additional area, and is suitable for various processes.
Smart Images
Figure CN223528045U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to amplifier technical field especially relates to a final stage impedance adjustable Ku wave band wideband high efficiency power amplifier. BACKGROUND
[0002] Ku wave band its frequency range is 12-18GHz, relative bandwidth 40%, is widely used in satellite communication, radar, seeker etc. In different system applications, the specific frequency range is also different, such as: 13.75-15GHz, 15-17GHz, 14-18GHz, the separate chip design for the complex frequency application demand of Ku wave band will undoubtedly increase the design cost and design cycle, and the performance of the chip covering the whole Ku wave band will deteriorate due to the impedance variation with frequency and gain roll-off characteristics of the transistor itself.
[0003] The traditional Ku wave band power amplifier structure as shown in Figure 1 It is composed of input matching network (IMN), transistor and output matching network (OMN), and the final stage impedance is fixed, the frequency range can cover 12-18GHz, but it is a compromise in power and efficiency, and the performance is greatly deteriorated compared with narrowband power amplifier. Figure 2 As shown in the structure, two power amplifiers of different frequencies are connected in parallel, and are switched by SPDT (single-pole double-throw switch) to realize different frequency applications. The traditional final stage matching network as shown in Figure 3 Wherein C1 is a bypass capacitor, C2 and C5 are direct-current blocking capacitors and do not participate in matching. According to Bode-Fano criterion:
[0004]
[0005] Wherein R and C are the resistance and reactance parts of the load. It can be seen that for a given load, the ratio of the reflection coefficient (Γ) of the matching network to the bandwidth is fixed, and the reflection coefficient deteriorates with the increase of the bandwidth, so the realization of wideband power amplifier is at the cost of output power and efficiency. UTILITY MODEL CONTENT
[0006] The utility model aims at overcoming the technical problems in the prior art, and provides a final stage impedance adjustable Ku wave band wideband high efficiency power amplifier.
[0007] The utility model aims at overcoming the technical problems in the prior art, and provides a final stage impedance adjustable Ku wave band wideband high efficiency power amplifier.
[0008] The application provides a Ku-band broadband high-efficiency power amplifier with adjustable final-stage impedance, wherein a matching network comprises an input end, a first inductor, a second capacitor, a third inductor, a fourth inductor, a fifth inductor, a fifth capacitor and an output end connected in sequence, a second inductor is connected between the first inductor and the second capacitor, a first capacitor is connected to the other end of the second inductor, a bias voltage is connected to the common connection point of the first capacitor and the second inductor, a third capacitor is connected between the third inductor and the fourth inductor, and a fourth capacitor is connected between the fourth inductor and the fifth inductor.
[0009] The first capacitor is grounded, the fourth capacitor is grounded, and the third capacitor is connected in series with a first field effect transistor and grounded.
[0010] In some embodiments, the gate of the first field effect transistor is connected to a gate voltage, the source of the first field effect transistor is grounded, and the drain of the first field effect transistor is connected to the third capacitor.
[0011] In some embodiments, a sixth capacitor is further connected between the third inductor and the fourth inductor, a second field effect transistor is connected in series with the sixth capacitor and grounded, and the first field effect transistor is connected in parallel with the second field effect transistor.
[0012] In some embodiments, the gate of the first field effect transistor is grounded, the drain of the first field effect transistor is connected to the third capacitor, and the source of the first field effect transistor is connected to a gate voltage; the gate of the second field effect transistor is grounded, the source of the second field effect transistor is connected to the sixth capacitor, and the drain of the second field effect transistor is connected to the gate voltage.
[0013] In some embodiments, the source of the first field effect transistor is further grounded through a seventh capacitor, and the drain of the second field effect transistor is further grounded through an eighth capacitor.
[0014] In some embodiments, the first field effect transistor and the second field effect transistor have the same size.
[0015] Preferably, the first field effect transistor and the second field effect transistor are both N-type field effect transistors.
[0016] Preferably, the equivalent resistance of the channel of the first field effect transistor is 0.8Ω.
[0017] Preferably, the equivalent capacitance of the first field effect transistor is 270fF.
[0018] Preferably, the gate voltage is 28V.
[0019] It needs to be further explained that the technical features corresponding to each option above can be combined or replaced to form a new technical solution.
[0020] Compared with the prior art, the utility model has the beneficial effects that:
[0021] (1) the utility model discloses based on the traditional topology, a field effect transistor is connected in series on the shunt ground capacitor, and the size of the branch capacitance value can be changed by controlling the gate voltage of the field effect transistor, the impedance point is different due to the opening and pinch-off of the field effect transistor, the impedance of the final stage matching network is changed, and it is adapted to different frequency bands, so that the function of the final stage impedance adjustable is realized, and the output power and efficiency of the wideband power amplifier can be greatly improved.
[0022] (2) the utility model discloses that two same size field effect transistors are connected in parallel at the impedance point, and the resistance value is further reduced.
[0023] (3) the utility model discloses that when EN (OFF) state, the power amplifier is in the range of 12-16GHz Output power is greater than 32.8dBm, and the efficiency is greater than 43.5%;In EN (ON) state, the power amplifier is in the range of 16-18GHz Output power is greater than 32dBm, and the efficiency is greater than 43%;And the traditional matching network is in the range of 12-18GHz, and the output power is greater than 31.2dBm, and the efficiency is greater than 39.5%. BRIEF DESCRIPTION OF DRAWINGS
[0024] Figure 1 It is the traditional Ku band power amplifier structure;
[0025] Figure 2 It is the improved Ku band power amplifier structure;
[0026] Figure 3 It is the traditional final stage matching network;
[0027] Figure 4 It is the final stage adjustable wideband matching network structure schematic diagram proposed by the utility model;
[0028] Figure 5 It is the equivalent circuit when FET is turned on and the equivalent circuit of the capacitor C3 branch;
[0029] Figure 6 It is the equivalent circuit when FET is pinched off and the equivalent circuit of the capacitor C3 branch;
[0030] Figure 7 The final stage adjustable wideband matching network structure is based on Figure 4 The schematic diagram of the proposed final stage adjustable wideband matching network structure is shown in the figure.
[0031] Figure 8 The final stage adjustable wideband matching network impedance variation circle is compared with the traditional matching impedance circle.
[0032] Figure 9 The output power comparison chart in three states is shown in the figure.
[0033] Figure 10 The power added efficiency PAE comparison chart in three states is shown in the figure. DETAILED DESCRIPTION
[0034] The technical solutions of the present application will be described clearly and completely below in combination with the drawings. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.
[0035] In the description of the present application, it should be noted that the directions or positional relationships indicated by "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like are the directions or positional relationships described based on the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.
[0036] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, "mounting", "connection" and "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meanings of the above-mentioned terms in the present application can be understood according to the specific circumstances.
[0037] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as there is no conflict.
[0038] Reference Figure 4In an exemplary embodiment, a Ku-band broadband high-efficiency power amplifier with adjustable output impedance is provided. The matching network of the Ku-band broadband high-efficiency power amplifier includes an input end, a first inductor L1, a second capacitor C2, a third inductor L3, a fourth inductor L4, a fifth inductor L5, a fifth capacitor C5, and an output end connected in sequence. A second inductor L2 is connected between the first inductor L1 and the second capacitor C2. A first capacitor C1 is connected to the other end of the second inductor L2. A bias voltage V d is connected to the common connection point of the first capacitor C1 and the second inductor L2. A third capacitor C3 is connected between the third inductor L3 and the fourth inductor L4. A fourth capacitor C4 is connected between the fourth inductor L4 and the fifth inductor L5.
[0039] The first capacitor C1 is grounded. The fourth capacitor C4 is grounded. A first field effect transistor FET1 is connected in series with the third capacitor C3. The gate of the first field effect transistor FET1 is connected to a gate voltage EN. The source of the first field effect transistor FET1 is grounded. The drain of the first field effect transistor FET1 is connected to the third capacitor C3.
[0040] Specifically, when the first field effect transistor FET1 is turned on, it is equivalent to a small resistance in series with a small inductance (which can be ignored). At this time, the equivalent circuit of this branch is a series connection of the third capacitor C3 and the resistance Ron, as shown in Figure 5 When the FET is pinched off, it is equivalent to a small capacitor in parallel with a large resistance (the resistance value is very large, and the radio frequency signal cannot pass through, so the resistance can also be ignored). At this time, the equivalent circuit of this branch is a series connection of the capacitor and Coff, as shown in Figure 6 The capacitance value of the branch increases. Therefore, by controlling the gate voltage EN of the first field effect transistor FET1, the capacitance value of the branch can be changed, thereby changing the impedance of the output matching network to adapt to different frequency bands. Figure 4 It can be seen that in the two working states of the first field effect transistor FET1, the impedances of nodes N1, N2, N3, and N4 are consistent. Starting from node N5, the impedance point is different due to the opening and pinching off of the first field effect transistor FET1, thereby realizing the function of adjustable output impedance.
[0041] In other examples, as shown in Figure 7 , the Figure 4The structure of the third inductor L3 and the fourth inductor L4 is improved, and the sixth capacitor C6 is further connected between the third inductor L3 and the fourth inductor L4, the second field effect transistor FET2 is connected in series on the sixth capacitor C6, and the first field effect transistor FET1 is connected in parallel with the second field effect transistor FET2. Wherein, the gate of the first field effect transistor FET1 is grounded, the drain of the first field effect transistor FET1 is connected with the third capacitor C3, and the source of the first field effect transistor FET1 is connected with the gate voltage EN; the gate of the second field effect transistor FET2 is grounded, the source of the second field effect transistor FET2 is connected with the sixth capacitor C6, and the drain of the second field effect transistor FET2 is connected with the gate voltage EN.
[0042] Further, the source of the first field effect transistor FET1 is further grounded through the seventh capacitor C7, and the drain of the second field effect transistor FET2 is further grounded through the eighth capacitor C8.
[0043] Specifically, Figure 4 The Ron and Coff of the field effect transistor are two parameters in inverse proportion, the smaller the Coff is, the larger the Ron is, if the FET tube cell with large Ron is used, the circuit performance will be deteriorated, therefore, when designing the matching network, a suitable capacitor value C is needed to be designed for capacitor distribution, C=C3+Coff, so that Coff meets the condition and Ron is small. The equivalent resistance of the finally selected FET tube cell is 0.8Ω, and the equivalent capacitance is 270fF, in actual use, two field effect transistors FET1 and FET2 with the same size are connected in parallel to further reduce the resistance value. At the same time, in order to reduce the requirement of the system to the power supply, the control voltage EN of the field effect transistor is changed from negative voltage-28V control to positive voltage+28V control, which is consistent with the drain supply voltage of the power amplifier.
[0044] Further, Figure 8 The Smith circle diagram of the impedance of EN(ON), EN(OFF) and the traditional matching network in the frequency range of 12-18GHz can be seen. It can be seen that in the EN(ON) state, the impedance is more biased to high frequency; in the EN(OFF) state, the impedance is more biased to low frequency; and in the traditional matching network, the impedance is not well matched at high frequency and low frequency because the whole frequency band needs to be considered. Figure 9 , Figure 10The output power and efficiency of the three states are compared. In the EN(OFF) state, the output power of the power amplifier is greater than 32.8dBm and the efficiency is greater than 43.5% in the range of 12-16GHz; in the EN(ON) state, the output power of the power amplifier is greater than 32dBm and the efficiency is greater than 43% in the range of 16-18GHz; and in the traditional matching network, the output power is greater than 31.2dBm and the efficiency is greater than 39.5% in the range of 12-18GHz; it can be seen that the structure proposed in the utility model has good performance in the entire Ku band, and can greatly improve the output power and efficiency of the wideband power amplifier.
[0045] The above specific embodiments are detailed descriptions of the utility model, which cannot be considered as limiting the specific embodiments of the utility model to these descriptions. For ordinary skilled in the art to which the utility model belongs, without departing from the concept of the utility model, a number of simple deductions and substitutions can be made, which should be considered as belonging to the protection scope of the utility model.
Claims
1. A Ku-band wideband high-efficiency power amplifier with adjustable output impedance, characterized in that, The matching network comprises an input terminal, a first inductor, a second capacitor, a third inductor, a fourth inductor, a fifth inductor, a fifth capacitor and an output terminal connected in sequence, a second inductor connected between the first inductor and the second capacitor, a first capacitor connected to the other end of the second inductor, a bias voltage connected to the common connection point of the first capacitor and the second inductor, a third capacitor connected between the third inductor and the fourth inductor, and a fourth capacitor connected between the fourth inductor and the fifth inductor. The first capacitor is grounded, the fourth capacitor is grounded, and a first field effect transistor is connected in series with the third capacitor and grounded.
2. The last stage impedance adjustable Ku-band wideband high efficiency power amplifier according to claim 1, characterized in that, The gate of the first field effect transistor is connected to a gate voltage, the source of the first field effect transistor is grounded, and the drain of the first field effect transistor is connected to the third capacitor.
3. The last stage impedance adjustable Ku-band wideband high efficiency power amplifier of claim 1, wherein, A sixth capacitor is further connected between the third inductor and the fourth inductor, a second field effect transistor is connected in series with the sixth capacitor and grounded, and the first field effect transistor and the second field effect transistor are connected in parallel.
4. The last stage impedance adjustable Ku-band wideband high efficiency power amplifier according to claim 3, characterized in that, The gate of the first field effect transistor is grounded, the drain of the first field effect transistor is connected to the third capacitor, and the source of the first field effect transistor is connected to the gate voltage; the gate of the second field effect transistor is grounded, the source of the second field effect transistor is connected to the sixth capacitor, and the drain of the second field effect transistor is connected to the gate voltage.
5. The last stage impedance adjustable Ku-band wideband high efficiency power amplifier according to claim 4, characterized in that, The source of the first field effect transistor is further grounded through a seventh capacitor, and the drain of the second field effect transistor is further grounded through an eighth capacitor.
6. The last stage impedance adjustable Ku-band wideband high efficiency power amplifier according to claim 4, characterized in that, The first field effect transistor and the second field effect transistor have the same size.
7. The last stage impedance adjustable Ku-band wideband high efficiency power amplifier of claim 4, wherein, The first field effect transistor and the second field effect transistor are both N-type field effect transistors.
8. The last stage impedance adjustable Ku-band wideband high efficiency power amplifier of claim 4, wherein, The equivalent resistance of the first field effect transistor is 0.8Ω.
9. The last stage impedance adjustable Ku-band wideband high efficiency power amplifier of claim 4, wherein, The equivalent capacitance of the first field effect transistor is 270fF.
10. The last stage impedance adjustable Ku-band wideband high efficiency power amplifier of claim 4, wherein, The gate voltage is 28V.