The device which couples the Electro-Magnetic Signal from main path of the waveguide is called waveguide directional coupler or waveguide coupler. This is required for monitoring purpose as well as to feed the signal to some other place.
Usually it will have 4 ports viz. input, output, coupled and terminated ports. The function of waveguide coupler is similar to RF directional coupler. Refer RF Directional Coupler for more information. Figure-1 depicts waveguide coupler.
There are various types of couplers such as cross guide, broad wall and side wall based on applications.
Following technical specifications need to consider for rectangular type of waveguide coupler.
• Operating frequency band
• Coupling value: 10 dB, 20 dB, 30 dB or 40 dB as desired
• Return Loss or VSWR: should be better
• Directivity: vary based on dimension, typical values are 10, 15, 20 and 25 dB
• Dimension: It should be choosen as per cutoff frequency needed as well as system with which it need to be interfaced.
Related links on waveguide coupler
RF directional Coupler basics and manufacturers, Refer following link:
RF Directional Coupler
RF power divider and RF power combiner basics and manufacturers refer following link:
RF Power Divider
For types of waveguide viz. rectangular & circular, waveguide propagation modes, impedance matching of waveguide read following waveguide tutorial.
waveguide basics tutorial
Manufacturers of waveguide components such as waveguide to coaxial adapter, coupler, flanges, gasket, tees, termination, shorts, isolator, circulator, horn antenna, attenuator, feed-thrus, bends, loads, twists, straights, pressure windows, transformers, sliding short circuits, fixed short circuits, sliding mismatches etc. visit following link.
Waveguide components manufacturer
Rectangular waveguide dimensions as per USA standard including frequency, broad dimension and narrow dimensions, visit following link.
Waveguide dimensions table
• The Waveguide Solution Limited, United Kingdom. Website: www.waveguidesolution.co.uk
• FLANN Microwave, Website: www.flann.com
• Connecticut Microwave Corporation, Website: connecticutmicrowave.com