A Portable Microwave Phase and Amplitude Test Set

Phase alignment at microwave frequencies may be made to 0.1?? or less, and amplitude balance to 0.1 dB may be made simultaneously with this fully solid-state test set which is designed to be comparable in size and weight to a Tektronix oscilloscope. Provisions are incorporated for testing with either pulsed or CW signals. Present means of measuring phase and amplitude differences at microwave frequencies require either rack size equipments or a group of various pieces of test equipment such as RF generators, standing wave indicators, and slotted lines. Standard procedures are to utilize slotted lines with VSWR sampling points using a short-circuited line or line-swapping arrangement. While these methods are versatile, all have limitations in resolution and accuracy while requiring long setup times and a high degree of skill by the operator. Operating at a single-crystal-controlled microwave frequency, this test set provides a means of continuously comparing two signals, one a reference or standard; the other a signal to be adjusted. The phase and amplitude difference between these two signals may be reduced to a null by adjusting the module under test while observing two zero-center balance meters. The signals may be read to ??3 dB and ??3.0?? or ??90?? full scale. Accuracy is better than 5 per cent for all scales, and the null resolution is ??0.05 dB and ??0.05??. A self-contained solid-state reference signal generator produces up to 3-watts power output from a balanced varactor double stage at 1296 Mc.