Limiters and Duplexers

Abstract

This chapter and the two which follow discuss the practical design of microwave control circuits using the PIN diode. From an organizational point of view, though, it would seem proper to have a chapter preceding these three device chapters in which the general methods of circuit construction would be addressed. In converting an equivalent circuit with computer generated theoretical performance into a practical device, a host of questions must be answered. The kind of circuit medium — waveguide, coax, stripline, microstrip, and so forth — must be determined. The method of introducing bias to the diodes, while separating it from the RF circuitry, may be with lumped conductors and capacitors or with distributed transmission line chokes. The diodes themselves may be used in chip form and bonded directly to the circuit ground plane, or packaged diodes may be employed. In short, there are a great many practical decisions to be made once the basic device equivalent circuit has been selected.