Coaxial Directional Couplers

Mega offers a full range of coaxial couplers to meet your varied requirements for power monitoring. Whether your need is for a vestigial loop type with a 6 dB per octave slope or a quarter-wave style offering you flat coupling over a 10% bandwidth, our couplers assure you years of trouble free service. The primary choice between the quarter wave or vestigial is based on the coupling requirements for your system to be able to accurately monitor the RF signal without overloading the detection equipment (typical maximum signals for detectors is 20 dBm, or 100 mW, without the use of RF attenuators). Quarter-wave couplers have tighter coupling, 15-30 dB, and can typically monitor RF signals up to 50-60 dBm, or 100-1000 W. Vestigial loop couplers are typically selected for monitoring RF powers greater than 1000 W. Both style couplers are available in either single coupler (monitor) type or dual directional (reflectometer) type. Custom configurations with three or more couplers are also available.


Quarter Wave Loop Coupler

7/8 Coaxial Directional Coupler

7/8 Directional Coupler/Monitor

Quarter-wave loop directional couplers offer a relatively flat coupling response over a 10% frequency bandwidth. Specific coupling factors in the range of 15-30 dB are easily attainable with 30 dB directivity at no additional costs. External loads are used and can be specified between 1 to 10 W to accommodate higher coupled power levels based on your requirements. Padding, or attenuation of the output RF signal prior to the detector is the responsibility of the user. All electrical data is traceable to the National Bureau of Standards. Typical electrical response of these couplers is listed below:


Typical Electrical Response
Coupling 15 - 30dB +/- 1 dB of Nominal
VSWR 1.05:1
Directivity 30 dB Nominal
Bandwidth 10%

Vestigial Loop Coupler



1 5/8 Vestigial Loop Coupler

1 5/8 Dual Vestigial Loop Coupler


The vestigial loop directional couplers are extremely compact and provide broadband RF measuring capabilities. The monitors and reflectometers exhibit a 6 dB per octave response. Units are available in 10 dB increments form 30 dB through 70 dB coupling factors and many other values are available at no additional cost. All electrical data is traceable to the National Bureau of Standards. Typical electrical response of these couplers is listed below:


Typical Electrical Response
Coupling 30 - 70 dB +/- 1 dB of Nominal
VSWR 1.05:1
Directivity 30 dB Nominal
Bandwidth 10%





Quarter Wave Coupler Options
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