4 - Transmit/Receive Modules

Abstract

This chapter discusses transmit/receive (T/R) modules. T/R modules constitute 50% of the overall array cost and 40% and 10% of the costs are apportioned to subarray manufacturing and array integration, respectively. The array designer is often confronted with many options that seem bewildering. The chapter attempts to untangle the many complex issues in a heuristic manner by defining the areas of broad agreement. One of the fundamental decisions an array designer has to take is whether to use solid state devices (SSDs) or tubes. It is widely accepted that SSDs are unchallenged for low-level signal processing functions. Similarly, SSDs are eminently suitable for low-noise amplifiers (LNAs). While all SSDs require some protection from high microwave powers, the LNAs are especially vulnerable and their protection is imperative in an electronic environment where intentional/unintentional jammers are encountered. A decision to use SSDs or tubes is usually based on a raft of considerations and not on just one device parameter. For space applications, the space qualification of a device is one of the important criteria the designer has to consider. Further, the chapter has delineated many thrusts that decrease the cost of monolithic microwave integrated circuits (MMIC)-based modules.