EW BrightSpark, James Henderson One Year On

James Henderson - Consultant, Antennas & Propagation

By: James Henderson
Consultant, Antennas & Propagation

27th February 2019

Home » Electronics Weekly

Following the BrightSparks award ceremony in May last year, most of my work has been on developing an electronically-scanned radar unit operating at mm-wave frequencies, applicable to autonomous ground and air vehicle monitoring and control. This has been a particularly interesting and challenging project as the design has been driven by a demanding requirement to create a small, low power, high performance sensor.

The key area of innovative design that I am particularly proud of is combining two 48-element antenna arrays on to the same PCB as the electronic circuitry. To achieve a low cost, the arrays are realised through a combination of 3D printing and PCB techniques.

This development posed many technical challenges owing to the often conflicting PCB-related requirements of antenna and RF circuitry. However, integration and performance benefits make this approach worthwhile.

System calculations

Initial work on this project required comprehensive system calculations to exactly understand the design requirements. System level planning is informative when determining how to distribute the required tasks.

Often, a number of subsystems could potentially solve the same technical challenge but only when looking at the problem as a whole can you assess how the elements of the system can best work together.

Scanning the radar beam

A key aspect of the design was how to scan the radar beam. In a previous project the antennas were mechanically moved to build up a 3D view of the scene. In contrast the new requirement was to scan the antenna beams electronically, which has many advantages over mechanically scanned systems. Electronic beamforming can be implemented digitally, at the analogue front end, or even within the antennas themselves.

In this design, the scanning mechanism was an integral part of the antenna array, which significantly simplifies other aspects of the system leading to a small sensor having low power consumption. However, this approach required lateral thinking when designing and constructing the PCB to achieve the target performance. For the first iteration of the design the electronics worked as intended, but the antenna performance was lower than expected.

Further investigation revealed the reason for the drop in performance and emphasised the many and varied challenges associated with working at mm-wave frequencies.

Special Interest

The second design iteration gave performance closely matched to my system calculations. This confirmed that the design operated as intended, which was extremely satisfying.

This whole process has exposed me to some particularly interesting design work and has consequently encouraged me to initiate a Special Interest Group within Plextek that specialises in the design and development of mm-wave electronic systems.

Following this project I expect to see substantial interest in operating at mm-wave bands, enhancing the capability of mm-wave circuits and I’m excited to be working with these cutting-edge technologies in the future.

The CEO of Plextek, Nicholas Hill, added:

“BrightSparks is a fantastic way to show your employees’ work is valued. It’s so important to get young people enthusiastic about their engineering careers and award recognition is a great motivational boost. The BrightSparks award last year won by James Henderson was well deserved and he has continued to shape his engineering career by contributing to key company projects here at Plextek.”

Following the BrightSparks award ceremony in May last year, most of my work has been on developing an electronically-scanned radar unit operating at mm-wave frequencies, applicable to autonomous ground and air vehicle monitoring and control. This has been a particularly interesting and challenging project as the design has been driven by a demanding requirement to create a small, low power, high performance sensor.

The key area of innovative design that I am particularly proud of is combining two 48-element antenna arrays on to the same PCB as the electronic circuitry. To achieve a low cost, the arrays are realised through a combination of 3D printing and PCB techniques.

This development posed many technical challenges owing to the often conflicting PCB-related requirements of antenna and RF circuitry. However, integration and performance benefits make this approach worthwhile.

System calculations

Initial work on this project required comprehensive system calculations to exactly understand the design requirements. System level planning is informative when determining how to distribute the required tasks.

Often, a number of subsystems could potentially solve the same technical challenge but only when looking at the problem as a whole can you assess how the elements of the system can best work together.

Scanning the radar beam

A key aspect of the design was how to scan the radar beam. In a previous project the antennas were mechanically moved to build up a 3D view of the scene. In contrast the new requirement was to scan the antenna beams electronically, which has many advantages over mechanically scanned systems. Electronic beamforming can be implemented digitally, at the analogue front end, or even within the antennas themselves.

In this design, the scanning mechanism was an integral part of the antenna array, which significantly simplifies other aspects of the system leading to a small sensor having low power consumption. However, this approach required lateral thinking when designing and constructing the PCB to achieve the target performance. For the first iteration of the design the electronics worked as intended, but the antenna performance was lower than expected.

Further investigation revealed the reason for the drop in performance and emphasised the many and varied challenges associated with working at mm-wave frequencies.

Special Interest

The second design iteration gave performance closely matched to my system calculations. This confirmed that the design operated as intended, which was extremely satisfying.

This whole process has exposed me to some particularly interesting design work and has consequently encouraged me to initiate a Special Interest Group within Plextek that specialises in the design and development of mm-wave electronic systems.

Following this project I expect to see substantial interest in operating at mm-wave bands, enhancing the capability of mm-wave circuits and I’m excited to be working with these cutting-edge technologies in the future.

The CEO of Plextek, Nicholas Hill, added:

“BrightSparks is a fantastic way to show your employees’ work is valued. It’s so important to get young people enthusiastic about their engineering careers and award recognition is a great motivational boost. The BrightSparks award last year won by James Henderson was well deserved and he has continued to shape his engineering career by contributing to key company projects here at Plextek.”

 

 

The MoD’s Defence Science and Technology Laboratory (DSTL) has contracted a team, led by Plextek Services including RFEL and 4Sight Imaging to tackle the problem of performing rapid evaluations of real-time image processing functions and to simultaneously demonstrate the latest adaptive capabilities that FPGA-based SoCs can deliver to defence and security surveillance applications.

Plextek features on Electronics Weekly website.

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