宽带毫米波系列延时器芯片设计

Design of broadband millimeter-wave True-Time Delay chips

摘要:

研究了数控延时器(TTD)芯片的基础原理及其在相控阵天线中的作用，基于GaAs赝配高电子迁移率晶体管(PHEMT)工艺，设计了2款宽带毫米波TTD芯片，改善宽带雷达的大扫描角度带来的波束空间指向色散问题。通过微波在片测试系统对两款系统所需的延时器芯片进行测试，结果显示，在32~40 GHz范围内，阵元级λ/64(5.625°)步进6位数控延时器的64态芯片插入损耗小于19 dB，64态延时相位误差为-2°~9°，插损波动小于±1dB，延时调节范围为0.446~28.125 ps(5.625°~354.375°)，全态输入输出驻波均小于1.5；子阵级0.25λ步进4位数控延时器的插入损耗小于12 dB，16态延时相位误差小于±12°，插损波动小于±1dB，延时调节范围为7.142~107.148 ps(0.25λ~3.75λ)，全态输入输出驻波均小于2.0；阵列级1λ步进3位数控延时器的插入损耗小于14 dB，8态延时相位误差小于-10°~22°，插损波动小于±1 dB，延时调节范围为28.57~200 ps(1λ~7λ)，全态输入输出驻波均小于1.8。这两款产品具有高频率、超宽带、大延时和小尺寸等优点，成功用于有源相控阵天线中。

Abstract:

The function and working principle of the True-Time Delay(TTD) chip has been studied and the chip has been applied in phased array radar. Based on GaAs Pseudomorphic High Electron Mobility Transistor(PHEMT) technology, three broadband millimeter-wave TTD chips are designed and fabricated. The measured results on wafer show that the 6 bit TTD provides 0.446 ps up to 28.125 ps in the frequency range 32 GHz-40 GHz, the TTD phase error for all 64 bit states is -2°~9°, the Insertion Loss(IL) is less than 19 dB, and the 64 states insertion variation is reduced to ±1 dB, the input and output Voltage Standing Wave Ratios(VSWRs) are better than 1.5 on the whole bandwidth; the 4 bit TTD provides 7.142 ps up to 107.148 ps in the frequency range 32~40 GHz, the TTD phase error for all 16 bit states is better than±12°, the IL is less than 12 dB, and the 16 states insertion variation is reduced to ±1 dB, the input and output VSWRs are better than 2.0 on the whole bandwidth; the 3 bit TTD provides 28.57 ps up to 200 ps in the frequency range 32~40 GHz, the TTD phase error for all 8 bit states is -10 °~22 °,the IL is less than 14 dB, and the 8 states insertion variation is reduced to ±1 dB, the input and output VSWRs are better than 1.8 on the whole bandwidth. The TTD chips are characterized with ultra wideband, large time delay and compact size, and mainly applied to wideband active phased array applications.