Receiving antenna in a waveguide

I want to draw significant amounts of power from a 150 MHz standing TE10 wave in a terminated waveguide. Should I use 1/4 λ center pin of a coax in an antinode or would it be better to place there an ensemble of resonant loop antennas?

Hello there:

If you really want to transmit 150 MHz via a rectangular waveguide, then the best way to introduce RF power into it or take it from it is to use the ordinary coaxial to waveguide transition designs. You can find many in the "classicaL' literature.
I would recommend "T.Moreno : Microwave Design Data" a nice book from `1950.
If you use a single-frequency signal, you can use a simple pin-type transition and using a coaxial stub tuner, you can adjust it to the best match.

My question is how you intend to realize your waveguide: 150 MHz corresponds to 2 meter wavelength, so your waveguide, if it utilizes the dominant TE-10 mode, will be pretty bulky. For a "high power" (you can think in megawatts ) ) your walls should be made of a copper sheet and to prevent loss, the rectangular cross-section should be kept without deviations over the full length.

UHF television with high power transmitters sometimes utilized waveguide sections; with ~ 0.5 meter wavelength, the waveguides looked like air-condition pipes. Yours will be much larger. What can be your purpose?

Currently I cannot disclose my purpose. I consider power levels several kilowatts, but more may also be of interest to me.
I have been informed that to introduce power to the waveguide I should use λ/4 center pin of a coxial cable. Should it be λ/4 measured from a bigger wall in the direction of the other bigger wall, or should it be placed symmetrically between bigger walls?

Dear htg:

I would recommend you to read some textbook on waveguide principles. You apparently have not heard that in a rectangular waveguide, the TE-10 mode wavelength is longer than that in the air.
Talking about a quarter-wavelength probe or antenna in a waveguide makes therefore no sense.
I would recommend again to follow the known technology like described in Moreno.

I have read that in a waveguide TE10 mode waves propagate at some non-zero angle Θ to the axis of the waveguide. Therefore their group velocity is c*cos(Θ), their phase velocity is c/cos(Θ) and the effective wavelength is λ / cos(Θ).

If the wave guide is "terminated", there is no standing wave. If you want standing wave, this means you want a cavity resonator?

I understand that to have a standing wave we have to have reflecting terminations on both ends. Yes, I want a resonant cavity - a terminated rectangular waveguide.