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Sep 08. Link Microtek is now offering a family of switch and limiter modules aimed mainly at military applications in the frequency range 2MHz to 20GHz.
Manufactured at Microsemi’s Microwave Products operation in Lowell, Massachusetts, the modules are based on the company’s own discrete diode components, which are fabricated at the same site using the latest process technologies. This in-house capability not only enables a wide variety of standard products to be offered but also means that customised modules can be quickly and easily produced to meet specific requirements.
The switch modules are available in four basic configurations covering SPST and SPMT designs: all series, series/shunt, all shunt and absorptive. Interconnects within the switches use thermal compression bonds or welds for maximum reliability, while connectorised units feature aluminium housings with soldered-in feedthroughs and hermetic SMA connectors. The limiter modules offer the systems designer a selection of passive RF limiters capable of operating over a broad spectrum of passband frequencies and handling up to 200W of pulsed power. Packages are designed specifically for integration into systems or subsystems and are readily adaptable for stripline, microstrip or surface-mount technologies. All the modules are designed to withstand the most demanding environmental conditions with regard to shock, vibration and humidity and can be hermetically sealed if required. They have an operating temperature range of -55 to +125degC.
26 Sep 08. McDowell Research®, an Ultralife® company, specializing in the design and manufacture of power solutions and accessories to support government and defense communications systems, introduces the MRC-200A and MRC-200H Tactical Repeater Systems, designed for portability and first-responder use with multi-band handheld radios. The “A” model uses the Thales MBITR AN/PRC-148 radio; the “H” model uses the Harris® FALCON III® AN/PRC-152 radio. In addition to greatly extending the range of a handheld radio—effectively providing performance comparable to a manpack radio—both models provide greater bandwidth coverage than all other commercial repeaters (30-512 MHz). This multiband capability allows the repeaters the ability to be used with virtually any hand-held radio as the outstation, while a field-interchangeable duplexer enables full duplex operation by combining both transmit and receive signals into a single antenna, providing added filtering for greater receive selectivity. Controlled by a MicroBlaze™ soft processor implemented on a Xilinx® Spartan®-3E FPGA (Field programmable Gate Array), the repeaters are a fully digital update to their analog predecessor. Both models employ a 4×16 LCD display for fault reporting, setup, RF power output, VSWR and DC voltage and current indications. An Ethernet interface allows for wired or wireless remote control and monitoring of all operating functions on a remote host-computer GUI. The backwards-compatible, smart-battery charging system uses SMBus technology to provide state-of-charge-indication (SOCI) on the LCD display or remote-host GUI and also allows for select non-SMBus batteries to be used. Both models can be powered via universal AC (85-265V, 47-63Hz) or DC (11-36V) with rechargeable battery backup. A smart power management system constantly monitors external vehicle DC power to dynamically control battery charging and internal-battery operation based on voltage levels detected. Both 12V and 24V DC systems have adjustable threshold settings to enable the internal battery chargers when the vehicle’s engine is running and disable them when the engine is turned off. Additionally, the vehicle’s DC voltage is constantly monitored to switch DC operation to internal batteries when it reaches a critical level, allowing—importantly—enough vehicle battery capacity to re-start the engine. The MRC-200A/H