Prana Amps Excel in Demanding HIRF Applications – High Power at Low Frequency
- November 13, 2019
- Posted by: Dominique
- Category: EMC Power Amplifiers
Every manufacturer has something at which they particularly excel. For Prana it happens to be meeting the demanding requirements of low frequency HIRF testing for MIL-SPEC and Avionics test standards. Producing field levels of 200 V/m or more at frequencies below 1 GHz, and especially at frequencies below 200 MHz, requires thousands of watts of reliable and clean RF power. At the lower frequencies the antennas and chambers become incredibly inefficient, presenting high impedances and high voltage standing wave ratio (VSWR) to the amp under the best of conditions.
Combiner Design Keeps the Smoke in the Box
Simple mistakes or setup anomalies can have devastating effects when thousands of watts of RF power are involved. Amplifiers may suddenly be forced to absorb all their own output power if a cable or connector is not properly installed or fails. This may cause a failure within the amplifier creating an imbalance on a combiner input causing it go into positive feedback until it burns itself up, but perhaps not before sending too much power to the next stage, cascading the failure throughout the amp in a catastrophic cascading failure. There is even an industry expression for this; “Letting the smoke out of the box”.
Prana amps of about 1,000 W or more, with an upper frequency of 1 GHz or lower, are uniquely designed for reliable operation in this difficult high power, high VSWR environment; preventing both catastrophic failure events and lower level degradation.
Spare User Replaceable RF Power Modules Inside
These amplifiers are built with 2 to 16 user replaceable RF power modules. Each power module can continue functioning (at a reduced power) with the loss of power transistor(s). The amp will notify the operator of this condition should it occur. Larger amplifiers have multiple stages of combiners. These combiners all designed to withstand an imbalance on their inputs without going into positive feedback and burning themselves up. Also, as a back-up, the combiners have a resistive connection between stages which will sacrifice itself should current exceed a threshold. These combiners make it impossible to have a cascading failure event. The smoke never comes out of a Prana amplifier!
Spare User Replaceable DC Power Modules Inside
Getting reliable DC power to bias all those RF power transistors is critical to reliable operation. Prana excels here too. There is a DC power supply system controller monitoring and assigning load to multiple DC power supply modules. There are anywhere from 1-10 redundant spare DC power supply modules (depending on amp size) available to the controller to draw on as needed. Of course, these are hot-pluggable supplies which can easily be exchanged by the user.
Diagnostic Monitoring & Notification
Prana amps constantly monitor RF power transistor bias voltage and current, RF power module temperature, power supply controller status, and more. Certain events will result in a notification to the user and continued operation. Others could result in a protective shut-down to prevent serious damage. All data can be accessed from front panel or diagnostic software delivered with the amp. Prana can even diagnose an amp remotely in more detail upon request. These diagnostics and notifications serve as a preventative measure identifying potential problems, enabling preventative measures by the user with support from HVT and Prana, with the amp still operational in their lab.
If you have ever suffered the cost and downtime of an expensive amplifier failure, then you should consider learning more about Prana amplifiers designed from the ground up to stay in your lab, where they belong.
Please contact email@example.com for more details.