RF System Design

Ensuring seamless wireless connectivity for communications, and solving challenging detection problems with radar

Radio frequency (RF) electronics is at the heart of modern communications and radar technologies – from mobile phones, radios and Wi-Fi to weather monitoring and air traffic control systems.

That’s why RF system design plays such a crucial role, ensuring that the RF signals required for transmission are generated accurately, and received against a background of noise and other unwanted signals.

It all starts with the intended use of the RF system, which will determine the required performance parameters. The first step is therefore requirements capture including, for example, data rate and desired range for a communication system, or detection range against particular targets for a radar system – along with size, weight and power considerations plus bill of materials cost.

Any system that makes use of the radio spectrum must also adhere to the relevant regulations and operating frequency plans, so the need for regulatory compliance also must be considered from the outset. This will be factored into the analysis of the requirements, to provide a sound basis for subsequent detailed design.

Real-world challenges

FOD detection radar system

Ensuring runways are kept clear of foreign object debris (FOD) is crucial in the aviation industry, as major damage can be caused if debris is sucked into an engine. But traditional visual inspections are time consuming and prone to human error.

When Plextek was asked to create a FOD detection radar for a South Korean airport, the first step involved researching the applicable regulations and available frequency allocations, then carrying out radar system calculations to arrive at recommended system parameters. The system was to remotely observe the many kilometres of operational runways of a major airport, detecting and reporting small foreign objects to an operator within tens of seconds of their appearance, and to centimetre accuracy – a very demanding requirement.

Specialist chip and wire construction techniques were used to overcome the challenges of designing and manufacturing transmitter and receiver modules operating at the chosen millimetre-wave (mmWave) frequencies.

Custom signal processing algorithms were also required to ensure the system could tell the difference between genuine debris and other objects in close proximity, such as runway signs and lights.

Smart Cities infrastructure

Plextek was tasked with designing a system for monitoring and control of city utility (Smart Cities) infrastructure. Sufficient communication range and capacity were identified as key requirements to reduce the infrastructure costs.

Existing protocols such as Wi-Fi were explored initially and found to be unable to provide the required range, so Plextek designed a proprietary radio protocol for the system – tailored to the application.

Starting with propagation models and regulatory factors, suitable operating frequencies were selected, and performance calculations led to requirements being derived for parameters such as transmitter power, receiver sensitivity and antenna gain.

The result was a custom radio transceiver and base station design, which has been successfully deployed across many cities in the UK and in the US to support smart city infrastructure.

Key skills

Measuring Radio Frequency (RF)
  • Capture of client requirements

    – and translation into engineering designs.

  • RF circuit design

    – from kHz to ~ 100 GHz.

  • PCB layout

    – including demanding high-frequency, mixed-signal designs with integrated antennas.

  • Standards-based design

    – integrating standard communications solutions.

  • Custom system design

    – to meet exacting customer requirements.

  • Complete systems

    – from antenna to back-end processing.

  • Component module/sub-circuit design

    – for integration into client systems.

  • Integration of antennas

    – into complex products.

  • Low SWaP-C

    – low size, weight, power and cost (SWaP-C).

Good RF systems design is the art of really understanding the problem, then identifying the applicable regulatory aspects and potential pitfalls, before arriving at a solution in which each element is specified with consideration of the consequences for the rest of the system.

Steve Greendale, Principal Consultant
Steve Greendale

Principal Consultant

What sets us apart when it comes to RF systems design?

The Plextek team has an in-depth understanding of the fundamentals underpinning modern communications, radar, telemetry and instrumentation systems, with the ability to distil practical engineering solutions from client requirements. Our expertise includes:

  • Radar
  • Communications
  • RF circuit design
  • mmWave radar
  • Microwave
  • EM simulation
  • Telemetry
  • Regulatory compliance

Examples of our RF systems design include:

  • Utility monitoring and control
  • Ground radar
  • Foreign object debris radar
  • Stolen vehicle tracking and recovery systems
  • Airborne data links
  • Airborne radar
  • Space-based radar
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