High-speed phase shifter with stable phase steps

The principle of operation and experimental results are presented for a microwave integrated diode phase shifter. The microwave-loss and SWR relationships are shown in two phase states for steps of 0 and 180 deg. The level of parasitic amplitude modulation does not exceed 0.3 dB in more than 30 percent of the frequency band, which is explained by the easy-to realize symmetry of the device. Total losses can be reduced to less than 0.8 dB only with a reduction of the operating-frequency band to 5-6 percent. It is noted that the device can be effectively used (at the 35-40 dB level) as an amplitude modulator with appropriate voltage switching on the pin-diodes.