**Abstract**

Compact wideband RF modules are crucial in mm-wave direction finding systems, radars, seekers, and communication systems. This chapter discusses new integrated wideband mm-wave RF modules. It also discusses the design and development of a compact wideband (18–40 GHz) frontend and a wideband (18–40 GHz) switch bank filter (SBF). The frontend electrical specifications determine the system signal-to-noise ratio and the system dynamic range. This chapter presents a low-cost integrated 18–40 GHz wideband compact frontend with a 47 dBm high power limiter. The frontend consists of two channels: a high gain and low gain channel. Wideband MMIC switches are employed to select the required channel. The gain of the high gain channel is around 27 dB with 1 dB flatness. The noise figure of the module is around 9 dB. This chapter also presents a low-cost, integrated, 18–40 GHz wideband compact SFB module. The wideband SFB consists of three wideband side-coupled microstrip filters. The SFB MIMIC switches operate in the 18 to 40 GHz frequency range and are used to select the required filter. The insertion loss of each filter section is less than 11.5 dB 1.5 dB. The novelty of this research is the development of compact, integrated wideband mm-wave RF modules for direction finding and communication systems.

**Keywords:** MM Wave Direction Finding System, Frontend, Filters, Wideband communication systems
