宽带毫米波矢量调制器MMIC设计

A Wideband Millimeter-wave Vector Modulator MMIC Design

矢量调制器由于在毫米波频段内具有的多级幅度和360°相位控制的特点，在毫米波直接载波调制和相控阵雷达系统应用中具有十分重要的作用。文中采用平衡式矢量调制器结构，对影响该调制器宽带平衡响应的关键参数进行了分析。通过研究Lange耦合器的耦合系数和均效应管开关管的尺寸对宽带平衡性能的影响，提出了一种宽带矢量调制器的设计方法。基于该设计方法，采用单片电路的实现方式，利用商用砷化镓70nmmHEMT工艺设计了一款工作在40GHz-80GHz的宽带毫米波矢量调制器微波单片集成电路。结果表明：在整个40GHz的带宽范围内，所设计的矢量调制器具有优于±4°的相位偏差和优于±0．4dB的幅度偏差。

Vector modulator has been increasingly an important component in millimeter-wave direct carrier modulation and phased- array radar applications, because of its capability of direct multilevel amplitude and 360° phase control at millimeter-wave frequen- cies. In this paper the key parameters on wideband performance are analyzed based on the balanced vector modulator topology. By investigating the effect of the coupling factor of Lange coupler and field-effect tube geometry on wideband symmetry performance, a novel design technique is proposed. Based on the proposed design technique, a wideband design of 40 GHz - 80 GHz vector modu- lator microwave monolithic integrated circuit is implemented in an commercial 70 nm mHEMT process. The simulation result shows that the phase error is less than ±4° and amplitude error is better than ±0.4 dB in the whole 40 GHz range.