SARAS Technology Ltd

SARAS Technology Designs Broadband and Efficient RF Power Amplifiers Using NI AWR Software


Company Profile

SARAS Technology Ltd, based in the UK, is a world-class designer and manufacturer of a broad range of custom RF/microwave components and subsystems used in a range of market sectors, including defense, broadcast, and wireless communications. 

The Design Challenge

Demand for multiple 5 - 10 W linear-coded orthogonal frequency-division multiplexing (COFDM) power amplifiers (PAs) covering the frequency range 1.5 - 2.8 GHz inspired designers at SARAS Technology to develop an approach for designing broadband and efficient RF power amplifiers (RFPAs) using optimal impedances and matching networks. An important parameter of these designs was to provide a typical linearity >25 dBc whilst maintaining the highest efficiency possible in output back-off mode. 

Moreover, in an increasingly competitive market, amplifier products must be delivered in a short timeframe and therefore a right-the-first-time design is becoming the norm rather than the exception. Coupled with time-to-market pressures is the need for the amplifier design to deliver performance based on customers’ original expectations. 

The Solution

SARAS Technology designers chose NI AWR Design Environment, specifically Microwave Office circuit design software, which greatly enhanced the design process and provided an accurate model of final amplifier performance, enabling the company to deliver its RFPA products to market quickly without compromising on performance. The design flow began with a thorough device selection and delineation process. This allowed an accurate identification of a “best candidate” device\technology prior to commencing the detailed design activities such as load pull, matching network synthesis, EM analysis, and layout.

The complete RFPA was then simulated using both the linear engine for small-signal gain and match, as well as the nonlinear engine for power simulations. Finally, the complete RFPA was laid out using the Microwave Office layout feature and a reference circuit was fabricated.

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