L波段GaN内匹配功率放大器研究
发布时间：2018-08-31 13:47
【摘要】：功率放大器通常位于射频前端发射机,将输入信号放大到足够功率电平以供天线对外辐射,对系统整机的性能至关重要。受限于传统半导体材料的性能缺陷,微波功放的输出功率有限;第三代半导体器件GaN HEMTs由于其宽禁带特性,具有高击穿电压、高电子迁移率以及适应高温环境等优点,在微波固态功率放大器领域有着巨大潜力。随着通信、雷达等系统的发展,对小尺寸大功率固态功放的要求也随之提高。内匹配形式的功放器件在体积和重量上优于外匹配功放,在研制难度和成本上优于MMIC功放;在如超大功率相控阵雷达的应用中,GaN HEMT内匹配功率模块在具有小体积的同时,还可实现大功率输出,使系统获得更强的远程作用能力。内匹配形式由于封装面积有限,复杂结构难以集成,同时这种现象在宽带低频时更加明显。因此,本文就L波段GaN内匹配功率放大器的设计进行研究,主要工作如下:功放工作频带达到一个倍频程,因此设计采用宽带匹配技术理论,对宽频带下阻抗匹配进行研究。对比传统宽带结构的优劣,选用在尺寸方面更具优势的多级低Q值低通LC匹配结构;针对小封装,功放电路输入输出将两路并为一路进行阻抗匹配;为使管芯之间相位幅度平衡,在两管芯两端直接进行功分合成;公式推导单级LC匹配网络参量计算式,并依据低Q宽带思想将公式应用于三级LC匹配网络,对源/负载阻抗进行中心频点的匹配,ADS电路仿真验证公式准确有效;推导计算公式将集总参量转为分布参量,进行ADS多频点宽带匹配仿真,实现功放1-2GHz范围的源/负载阻抗匹配。最终设计并制作一款L波段GaN基内匹配功率放大器。管芯选用国内某公司自主研发的大栅宽GaN HEMT;匹配网络中,电容器采用金属-绝缘层-金属(MIM)实现,电感采用高阻线实现,使用金丝进行键合。功放封装在14.5mm*14.5mm的管壳中,工作在1-2 GHz,偏置在VGS=-2.8V、VDS=28V,对高温(85℃)、常温(25℃)环境温度下,实测连续波模式输入Pin=37dBm时,均有输出功率Pout45dBm、漏极效率ηD44%;低温(-55℃)时更有输出功率Pout47dBm、漏极效率ηD52%;小信号增益带内均大于10.5dB。与传统使用T型网络对端口阻抗进行输入预匹配,再结合电桥或Wilkinson功分器进行两路合成实现宽带匹配相比,本文使用的匹配结构可以集成在更小的封装内。
[Abstract]:The power amplifier is usually located in the RF front-end transmitter. It is very important for the whole system to amplify the input signal to a sufficient power level for external radiation of the antenna. The output power of microwave power amplifier is limited due to the performance defects of traditional semiconductor materials, and the third generation semiconductor device GaN HEMTs has the advantages of high breakdown voltage, high electron mobility and high temperature environment due to its wide band gap. There is great potential in the field of microwave solid-state power amplifier. With the development of communication, radar and other systems, the requirement of small-size high-power solid-state power amplifier is raised. The internal matching power amplifier is superior to the external power amplifier in volume and weight, and is superior to the MMIC power amplifier in the development difficulty and cost. For example, in the application of super large power phased array radar, the matching power module of gan HEMT has small volume. It can also achieve high power output, so that the system can achieve stronger remote operation ability. Due to the limited packaging area, it is difficult to integrate the complex structure, and this phenomenon is more obvious in the broadband low frequency. Therefore, the design of L-band GaN internal matched power amplifier is studied in this paper. The main work is as follows: the working band of power amplifier reaches a frequency doubling path, so broadband matching theory is adopted to study impedance matching in wide band. Comparing the advantages and disadvantages of traditional wideband structure, the multi-stage low-Q low-pass LC matching structure with more advantages in dimension is selected, and for small package, the input and output of power amplifier circuit will match the impedance together. In order to balance the phase amplitude between the tube cores, the power division synthesis is carried out directly at both ends of the two cores, the formula for calculating the parameters of the single-stage LC matching network is derived, and the formula is applied to the three-stage LC matching network according to the low-Q broadband theory. The simulation results of central frequency points matching ads circuit for source / load impedance show that the formula is accurate and effective, and the formula is derived to convert the lumped parameters into distributed parameters, and the ADS multi-frequency wideband matching simulation is carried out. The source / load impedance matching in the 1-2GHz range of power amplifier is realized. Finally, a L band GaN power amplifier is designed and fabricated. In the large gate width GaN HEMT; matching network developed by a domestic company, the capacitor is realized by metal-insulator-metal (MIM), the inductance is realized by high resistance wire, and the gold wire is used for bonding. The power amplifier is encapsulated in the tube and shell of 14.5mm*14.5mm, working in 1-2 GHz, bias at the ambient temperature of high temperature (85 鈩，
本文编号：2215175
[Abstract]:The power amplifier is usually located in the RF front-end transmitter. It is very important for the whole system to amplify the input signal to a sufficient power level for external radiation of the antenna. The output power of microwave power amplifier is limited due to the performance defects of traditional semiconductor materials, and the third generation semiconductor device GaN HEMTs has the advantages of high breakdown voltage, high electron mobility and high temperature environment due to its wide band gap. There is great potential in the field of microwave solid-state power amplifier. With the development of communication, radar and other systems, the requirement of small-size high-power solid-state power amplifier is raised. The internal matching power amplifier is superior to the external power amplifier in volume and weight, and is superior to the MMIC power amplifier in the development difficulty and cost. For example, in the application of super large power phased array radar, the matching power module of gan HEMT has small volume. It can also achieve high power output, so that the system can achieve stronger remote operation ability. Due to the limited packaging area, it is difficult to integrate the complex structure, and this phenomenon is more obvious in the broadband low frequency. Therefore, the design of L-band GaN internal matched power amplifier is studied in this paper. The main work is as follows: the working band of power amplifier reaches a frequency doubling path, so broadband matching theory is adopted to study impedance matching in wide band. Comparing the advantages and disadvantages of traditional wideband structure, the multi-stage low-Q low-pass LC matching structure with more advantages in dimension is selected, and for small package, the input and output of power amplifier circuit will match the impedance together. In order to balance the phase amplitude between the tube cores, the power division synthesis is carried out directly at both ends of the two cores, the formula for calculating the parameters of the single-stage LC matching network is derived, and the formula is applied to the three-stage LC matching network according to the low-Q broadband theory. The simulation results of central frequency points matching ads circuit for source / load impedance show that the formula is accurate and effective, and the formula is derived to convert the lumped parameters into distributed parameters, and the ADS multi-frequency wideband matching simulation is carried out. The source / load impedance matching in the 1-2GHz range of power amplifier is realized. Finally, a L band GaN power amplifier is designed and fabricated. In the large gate width GaN HEMT; matching network developed by a domestic company, the capacitor is realized by metal-insulator-metal (MIM), the inductance is realized by high resistance wire, and the gold wire is used for bonding. The power amplifier is encapsulated in the tube and shell of 14.5mm*14.5mm, working in 1-2 GHz, bias at the ambient temperature of high temperature (85 鈩，
本文编号：2215175
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