Technical memorandum: New frequency dependent equivalent circuit for gap discontinuities of microstriplines

Gap discontinuities in microstrip lines are widely used but the equivalent circuit representation used is not good enough for wideband microwave integrated circuits. In this paper a new multi-element circuit is introduced which has frequency dependent parameters and includes a radiation resistance. All the parameters can be determined using semi-empirical formulas which are developed in the paper. Experimental and theoretical results up to 15 GHz were found to be in excellent agreement.