Design of transfer impedance test fixture accurate through 10 GHz

A transfer impedance test fixture for testing of EMI (electromagnetic interference) gaskets has been designed where the upper test limit is above 10 GHz. The design incorporates a type `N´ UG-29 coaxial connector to obtain a 50 ohm transmission line characteristic impedance and terminates the line into a plate which can retain gaskets as small as .28 inches in diameter. A 50 ohm resistor certified to 18 GHz is used as a terminator for the signal. The result is a transfer impedance text fixture which consists of a 50 ohm matched cavity terminated into a 50 ohm load certified to 18 GHz. Reflectometer test results indicate that the voltage standing wave ratio of the transfer impedance test cavity is approximately 1.2 at 12 GHz. The results of measuring a 3 ohm calibrated resistor and an EMI gasket are presented and show no significant resonance. The measurements are taken using spectrum analyzer and sweep generator techniques