HASCO and Werbel - A Dynamic Partnership

Quality Meets Efficiency: Elevating Standards in Manufacturing and Distribution.

Werbel Microwave provides a wide selection of Couplers for your application needs - from laboratory test and measurement, to defense and military.  With broadband flat coupling response, high directivity, and excellent return loss performance we offer reliable solutions to meet your requirements.

Directional couplers are used for monitoring signals.  They can be installed within a trunk line and allow accurate sampling of the RF signal while minimally impacting performance of the system.  They are available in various configurations including single directional, bidirectional and dual directional.

Single Directional

A coupler may be used to monitor an input signal.  Consider an active device that required the input power not to exceed +10dBm, otherwise damage may occur.  A coupler may be placed at the input, directly before the device to be protected. 

The coupled signal may them be fed into an RMS detector, which converts the coupled power into a voltage that is directly proportional to the input power level. 

An op-amp comparator circuit is used to drive a TTL signal when the input power is too high.  This TTL signal may then be used to shut off the device, thereby protecting it from input power over load.

Bidirectional

The bidirectional coupler is constructed similarly to the single directional coupler with the termination omitted.  This allows a signal travelling in the reverse direction to be coupled to the reverse port.  It is important to know that the forward and reverse ports are electrically and physically connected to each other.  Thus, there is no isolation offered between the forward and reverse ports.  

The user may “bring their own load” to connect to the reverse port, effectively converting the coupler to a single directional coupler with higher reverse power handling capability.  However, care must be taken to ensure the load has excellent VSWR performance, as it will impact directivity of the coupler.

Dual Directional

In the dual directional coupler, the forward and reverse coupled outputs are independently isolated.  Effectively, there are two single couplers connected back-to-back, in a single enclosure.  The key difference between the dual directional and the bidirectional couplers is that in the dual directional, each of the coupling lines is independently connected to its own termination.  Which means that a mismatch on one coupled port will not affect the other. This is a useful characteristic in amplifier power monitoring applications where a good VSWR cannot always be guaranteed at the detector input.

The dual directional coupler may be used to monitor and control the output power level of an amplifier.

In this circuit, the dual directional coupler is placed immediately after the power amplifier.  Both the forward and reverse power is monitored simultaneously.

The forward monitor may be used in a negative feedback loop to regulate the amplifier’s output power.  In this example:

• The RMS detector converts the coupled power to a proportional voltage.
• An op-amp scaling circuit converts the voltage slope to drive the voltage-variable attenuator (VVA).
• The VVA increases attenuation proportional to the voltage applied, which reduces the amplified signal.

The reverse monitor may be used to protect your expensive amplifier from an open/short or bad load VSWR condition at the output.

• If a reflected signal of high power is coupled to the reverse port, it creates a proportional voltage at the RMS detector out.
• This voltage is fed into an op-amp comparator, which outputs a TTL signal when the input voltage is above the threshold.
• The TTL signal controls the power supply voltage to the power amplifier, shutting it off. 
• The power supply shutdown could be implemented using a relay or MOSFET. 

HASCO is the exclusive distributor for Werbel Microwave Directional Couplers.

Couplers

Up to 20 GHz

All Werbel products feature:

• Optimized Design
• High Isolation
• Maximum Efficiency
• Clean Signal Integrity
• Reliable Repeatability
• Imperceptible Reflection

Werbel Microwave maintains a lean, US-based manufacturing facility with the latest technology of network analyzers, pick and place, solder reflow, and laser engravers, allowing for greater efficiency and streamlined in-house processes to control quality and shorten lead times.  Werbel Microwave is also ISO: 9001:2015-certified, so when you buy our new directional couplers and power dividers, manufactured by Werbel Microwave and distributed solely by HASCO, you know you’re getting a quality product.