What is the principle of 8753's test port coupler?
I found the pics in this site:
http://www.union-rnd.com/8753e8753es...B%86%E8%A7%A3/
I also have the schematic diagram of 8753A/C's coupler:
they are so different.
What is the principle of 8753's test port coupler?
Part of the sweep input goes to the instrument, part goes to a RF bridge which has a precision termination inside and a test port to the outside world. The unbalance output from the bridge goes to the instrument.
So if you use the sweep as your horizontal time base, then if you have a good match on the test port, the output would be low right across the swept frequency for your vertical deflection. If the test port was open circuit then the output would be high across the swept frequency. The attenuator allows the scale to be calibrated. If some other circuit was connected to the test port then the display would show humps and troughs. If the instrument can measure the phase of the two RF sources then the exact impedance (C or L) could be found or a Smith chart displayed.
Frank
I know this basic theory. I want to know the principle of 08753-60365.Forgive of having little talent and less learning,I am so puzzled about this coupler.