Nujira’s Military PA Platform Halves Power Dissipation
The firm’s first PA (Power Amplifier) platform for the military has set a new benchmark for the size and weight of the batteries and extended usage time for troops.
Nujira has released its first PA platform for military communications, halving the power dissipation for a transmitter covering an entire frequency octave. Such a transmitter can be built using just using just one PA device together with a Coolteq power modulator module.
Tim Haynes, CEO of Nujira said, "New military net-centric communications systems provide a secure rapid flow of voice, data and video information and offer reliable, good quality coverage over wide bandwidths. This transmission environment is especially challenging, as the required operating frequency range is very wide and the Peak to Average Power Ratio (PAPR) is high. Delivering such a major efficiency improvement is a significant achievement, and offers military communications systems designers and users a considerable advantage by reducing the size and weight of the batteries required and/or extending the usage time."
The Nujira military PA platform uses an RFMD RF3934 PA device together with a Coolteq.h envelope tracking (ET) modulator module. The performance of this platform was compared to the performance of the same transistor in fixed drain configuration over an operating frequency range of 225 to 450 MHz, with signals with a very high peak to average power ratio (PAPR) of 10 dB.
Using the Nujira ET module, the amplifier showed an efficiency improvement from 25% to 40% (which represents a halving of the power dissipation) and, as an additional benefit from ET, delivered 1.5 to 2 dB more peak power.
The waveforms used in the new networked battlefield communications protocols are usually OFDM or QAM based and support frequency hopping and adaptive signal to noise encoding schemes. For example, the Wideband Networking Waveform (WNW) specified by JTRS for ground to ground and ground to air communications and the Tactical Targeting Network Technology (TTNT) used for airborne sensor, shooter and ordnance communication is based on the OFDM modulation scheme.
The Soldier Radio Waveform (SRW) for soldier to soldier communications is based on QAM modulation. The MUOS (Mobile User Objective System) for satellite to ground, sea or air communication uses both OFDM and QAM, and leverages the W-CDMA technology developed commercially for existing mobile phone networks.