HP-Agilent/Keysight 775D

The HP 770-series Couplers cover frequency spreads of more than two-to-one, each centered on one of the important VHF/UHF bands. With their high directivity, these couplers are ideal for reflectometer applications. Re- flectometers can save appreciable time in the design and manufacture of broadband antennas, ECM equipment, tele- vision receivers and transmitters, etc. The close tracking of the auxiliary arms makes these couplers particularly useful for reflectometers driven by externally-leveled sweep oscillators such as the H P 8690 series. The forward signal is detected and used to level the output of the sweep oscillator while the reflected signal, after detection, is applied to a display device such as an oscilloscope or graphic recorder. Changes in the leveled power due to the coupling variation in the forward arm are virtually cancelled by a similar coupling variation in the reverse arm. The couplers are also capable of materially improving the speed and accuracy of power measurements because of their accurate coupling and low SWR. The units are capable of handling fairly high amounts of power and have low inser- tion loss so they can be permanently installed in coaxial lines for continuous monitoring. Also, a power meter can be al- ternately connected to the “incident” and “reflected” ports to aid in adjusting for maximum forward power.