Young Engineer Sponsorship: The ARMMS RF & Microwave Society provides sponsorship for young engineers (28 or below) who have had papers accepted for presentation at each meeting. Sponsorship is £200 cash plus free attendance (including conference dinner and overnight accommodation). Potential candidates should identify themselves as eligible at time of submission and state their date of birth. This offer is limited to a maximum of 2 places per meeting.
Best Paper Award: The Steve Evans-Pughe prize is awarded to the best presenter at each meeting. The prize is sponsored by Cadence.
Best Female Presenter Award: The Katharine Franck Huettner prize for best female presenter is sponsored by Microwaves101. Its aim is to encourage and support female engineers. The prize was initiated in November 2024 and takes the form of a 200 dollar award.
If you are interested in submitting a paper for presentation at this conference, please contact the technical coordinator (details below). Papers currently listed below are those already accepted. The deadline for submissions is 14th of March 2025. For exhibition enquiries please email exhibition@armms.org, for all other enquiries please email enquiries@armms.org
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Double Tree by Hilton Oxford Belfry
The Oxford Belfry
Nr Thame
Oxfordshire
OX9 2JW
| Web | https://www.theoxfordbelfry.co.uk |
Farshad Eshghabadi
Viper-RF
| farshad.eshghabadi@viper-rf.com |
A Novel Method for Over-The-Air Characterization of On-The-Move Beamforming Systems | |
| Benjamin Falkner and Dan Harman | |
| Satellite Applications Catapult | |
As beamforming systems become a far more commonplace component of satellite and terrestrial communications, characterising such systems while in motion is an increasingly important part of the testing and verification process. However, existing over-the-air antenna measurement methods can not yet fully measure the de-pointing of fully integrated antennas and beamforming networks. To this end, a novel measurement system called the “Comms on-the-move Electronically Steerable Antenna Testing” (CESAT) is in development. This system aims to provide the accurate emulation of a satellite signal with a bespoke array and vehicle motion using a motion platform. The system then measures the de-pointing error of the terminal in real time using a novel measurement array and algorithm. This paper presents the CESAT concept and specification at its current stage and an analysis of the de-pointing estimation method developed for the system. Analysis of this algorithm is presented to demonstrate how the range and density of the measurement array can impact the accuracy of the system for antennas of various beamwidths. | |
Characterisation of dielectric materials using waveguide transmission line and MCK methods | |
| xiaobang.shang@npl.co.uk | |
| NPL | |
Quad Flat No-lead (QFN) packaging is a widely used technology for housing high-frequency circuits due to its ability to minimise electromagnetic interference, ensure signal integrity, and provide stable RF performance. During the design phase of packaged devices, knowledge of the mould compound’s dielectric properties is essential for accurately modelling encapsulated circuits. However, typical mould compound datasheets provide measured values only at relatively low frequencies, limiting their usefulness for high-frequency applications. In this work, the dielectric properties of three different mould compounds were measured at microwave and millimetre-wave frequencies using two VNA-based guided-wave techniques. The waveguide transmission line method was used for measurements in the 18 GHz–26.5 GHz range, while the material characterisation kit (MCK) method was employed for the 50 GHz–110 GHz range. The study focused on the real part of the relative permittivity (ε′) and the loss tangent (tan δ). To investigate the effects of moisture ingress, material samples were measured both before and after vacuum baking, and the results were compared. This work could find useful applications in the design of high frequency planar circuits involving packaging materials. | |
Design and Construction of a Wideband (0.45-1.6GHz) Horn Antenna for NPL for Power Flux Density Calibration | |
| Harold Thieba | |
| Link Microtek | |
The EMC shielding and testing market is steered by the growing demand and ever-evolving need for advanced electronic devices and complex systems across various industries; Automotive, Telecomm, Defence, and Medical, to name a few. Amidst the technological advancements in these sectors, ensuring personnel are not exposed to harmful levels of RF or microwave radiation is crucial for compliance with Health and Safety regulations.
This presentation examines the design, through 3D EM software, and construction, of a wideband horn antenna used for antenna calibration. The antenna was designed by Link Microtek in collaboration with the National Physics Laboratory (NPL), the end user, who sought a custom design for an antenna which would provide higher gain, required for certain automotive standards. The numerous electrical and mechanical design challenges involved, such as ensuring high gain, low VSWR and a wide operating bandwidth, along with controlling weight and size are presented and discussed. | |
Design aspects of a wideband RF Front-end for an Adaptable Radio Platform | |
| Rucha Smith | |
| Slipstream | |
The continually increasing demand for high data rates, low-latency and high user density has contributed to the rapid evolution of radio standards, generating a need for flexible, high-performance platforms that can dynamically access different parts of the radio spectrum for a variety of applications and operations. A software-defined radio (SDR) platform provides an elegant solution by offering functional flexibility and application adaptability through reconfigurable hardware. The key challenges in achieving a reconfigurable platform lie in the implementation of the RF front-end hardware. A reconfigurable front-end requires tunable components that can operate over wide bandwidths without compromising performance. With the high peak-to-average ratios (PAPR) of the increasingly complex modulation schemes, balancing efficiency and linearity becomes increasingly challenging.
This paper presents an AMD RFSoC based adaptable radio platform with a particular focus on the wideband, tunable RF front-end operating in the 5G New Radio (NR) N78 and N77u bands, i.e., 3.4 – 4.2 GHz. Investigations into the key challenges and performance of a digitally controlled low-power RF front-end (LP-RFFE) with 8 transmit and 8 receive channels are presented. | |
Design of a W-Band Up-Down Converter for Automotive Radar Testing | |
| Vlad Marinov | |
| EECL | |
W-band frequencies (71 GHz - 86 GHz) have seen
a significant rise in interest, driven by applications such as
automotive radar, satellite communications, and high-capacity
mobile networks. This has resulted in an increase in demand
for test equipment in this band, with a particular focus on highly
integrated, lower-cost solutions.
This paper presents the design of an up-down frequency
converter from K-band to W-band, with a shared local oscillator
(LO) enabling coherent (frequency-and-phase-locked) up-down
conversion. The design also includes Built-in Self Test (BIST)
functionality, featuring an internal self-test loopback mode
and output power measurement. The converter utilizes heater
temperature stabilization for long-term, calibrated performance
and verification in a wide-range of operating environments.
In conjunction with a DC to K-band Dual Channel Frequency
Extender developed by EECL, a modular system is created to
extend low-frequency test equipment capabilities up to W-Band.
The system was initially developed for production-line testing of
automotive radar chips, but is also suitable for other applications,
such as W-band radar frontends, spectrum analyzer extenders,
and VNA extenders. | |
Experimental Demonstration of Split-Gate GaN HEMT Device in Ku-band | |
| Aquila G. Powell | |
| Cardiff University | |
In this paper, the split-gate device architecture is explained and tested experimentally by means of load-pull characterisation at 17 GHz of a GaN prototype of the device. It provides reconfigurable output power by manipulating the bias voltage, without changing the input power, and while maintaining efficient operation. The measurements demonstrate an output power tunability of approximately 5 dB between modes of operation on a fixed load, over an input power range of 30 dB. In the high power state, all gates were biased at class AB with 20 Vdc drain bias, 40 mA quiescent current and the low power state, half of the gates were pinched off and the drain bias reduced to 12 Vdc, 20 mA quiescent current which optimises the load-line, maintaining efficiency. | |
Experimental Demonstration of Split-Gate GaN HEMT Device in Ku-band | |
| Aquila G. Powell | |
| Cardiff University | |
In this paper, the split-gate device architecture is explained and tested experimentally by means of load-pull characterisation at 17 GHz of a GaN prototype of the device. It provides reconfigurable output power by manipulating the bias voltage, without changing the input power, and while maintaining efficient operation. The measurements demonstrate an output power tunability of approximately 5 dB between modes of operation on a fixed load, over an input power range of 30 dB. In the high power state, all gates were biased at class AB with 20 Vdc drain bias, 40 mA quiescent current and the low power state, half of the gates were pinched off and the drain bias reduced to 12 Vdc, 20 mA quiescent current which optimises the load-line, maintaining efficiency. | |
From the Laboratory to Application ? Engineering the Solid State MASER | |
| Kingshuk Mallick and Paul Farrar | |
| Nascent | |
Interest in sovereign position navigation and timing (PNT) systems has increased significantly recently and the ability to demonstrate high precision, low drift RF signals in a low power, compact footprint is a key enabling technology. The development of Microwave Amplification by Stimulated Emission of Radiation (MASER) technology has demonstrated high accuracy timing systems that can be found in a range of applications. However, these systems are physically large and require highly protected environments, making them unsuitable for use in a wide range of applications. Atomic defects in wide bandgap semiconductors, such as diamond and silicon carbide (SiC) have demonstrated MASER behaviour. The frequency of the emission is controlled by the zero-field splitting of the defect energy levels, which is described using quantum mechanics and the applied magnetic field, resulting in a linewidth that is specified by the Schalow-Townes limit. A further advantage of the MASER is the level of flexibility in the pump LASER, with a significant degree of ambivalence in the wavelength and stability requirements in comparison to conventional atomic and quantum based timing systems.
We report on the development of a MASER based timing system, where the RF signal is generated by the emission from silicon vacancy defects in 4H-SiC and the subsequent integration with RF down-conversion circuitry, to generate a stable 10 MHz timing signal suitable for PNT applications. The manufacture of the defects in SiC by means of hydrogen and helium implantation results in either high defect concentration or long lifetimes, which are a prerequisite for population inversion and the optimisation of the process conditions is a key enabler. The volume of the resonant cavity used to form the MASER is reduced using a high dielectric constant dielectric resonator, however this introduces significant variation between units due to manufacturing tolerances, as well as introducing a significant variation in performance with temperature.
We report on the development of a MASER suitable for deployment outside of a laboratory setting and the challenges of ensuring a stable RF performance that is characterised through the use of the MASER as an amplifier, similar to the passive MASER systems used in space based timing systems. This includes the restrictions in the manufacturing and operating tolerances of the system, along with the performance in real world ambients that are specified by EMC and vibration test requirement | |
How to Make Microwave Hardware Sustainable: Manufacturing, Circularity, and Life-Cycle Assessments | |
| Mahmoud Wagih | |
| University of Glasgow | |
Wireless networks are a major energy consumer; the underlying microwave frontends are dependent on specialised RFICs/MMICs fabricated in materials and energy-hungry semiconductor processes, and are reliant on a finite resource of critical rare metals (CRMs). This talk introduces directions towards more sustainable wireless RF frontends, identifying decarbonisation hotspots from ICs to PCBs. An introduction to Life Cycle Assessments (LCAs) of microwave electronics will be provided, showing the trade-off between node, cut-off frequency, and embodied carbon. Finally, examples of recyclable and fully “circular” microwave devices will be showcased, demonstrating ways of re-using ICs and recovering CRMs, from microwave circuits, using novel board and package-level solutions. | |
Improving Two-Way Radio (TWR) PA linearity using a Cartesian Feedback Loop | |
| Yashar Alimohammadi | |
| CML Microcircuits UK | |
This paper presents the linearization of a Two-Way Radio (TWR) communication power amplifier (PA) using the CMX998 Cartesian Feedback Loop (CFBL) integrated circuit. The CMX998 enables the implementation of an analogue CFBL around the PA, enhancing its linearity for narrowband modulated waveforms. To demonstrate its capability, the CMX981 is employed to generate a DQPSK-modulated signal, validating the system’s performance with standard waveforms. The transmitter operates across a frequency range of 30 MHz to 1 GHz, supporting a full 360-degree loop phase shift. CFBL is typically designed for signal bandwidths of up to 200 kHz, making it suitable for narrowband applications.
The proposed test system is applied to linearize the CMX90A007 and CMX90A009 power amplifier lineup designed for TWR network, which delivers 10 W of output power and 17dB gain in the 400–470 MHz range. The in-band and out-of-band linearity of the PA lineup is analysed, demonstrating an improvement of ACLR and EVM by 20 dB and 10 % using the CMX998, ensuring a highly linear output signal for two-way communication systems. | |
Linearizability for Power Amplifiers with Wide Instantaneous Bandwidth | |
| Eva Ribes-Vilanova | |
| Keysight | |
This paper explores challenges and solutions in amplifying signals with wide instantaneous bandwidth, focusing on the linearization and power efficiency techniques for power amplifiers. We will discuss the impact of wideband signals on amplifier performance and present advanced EDA tools and strategies to predict amplifier behaviour under modulation and digital predistortion (DPD). These approaches are essential for optimizing performance in modern communication systems. | |
Made in Space | |
| Darren Cadman | |
| Space Forge | |
For over 50 years, state funded space agencies have conducted experiments on crystal growth in space, encompassing pharmaceuticals, alloys and semiconductors. The trend observed and summarized in the NASA/Butler University study of >160 in-space inorganic semiconductor crystal growth experiments show that manufacturing in low earth orbit (LEO) can transform quality through consistent improvements in size, purity and crystalline structure over those grown terrestrially.
Space Forge was founded in 2018 with the aim of realising the commercial opportunity of growing semiconductor materials in space for terrestrial applications. As such it is a global first mover in the pursuit of developing a commercial in-space manufacturing (ISM) capability and realising its economic benefits. With the increasing geo-political tensions particularly regarding semiconductors and their supply chains, in 2024 Space Forge secured its Series A investment that was led by the NATO Innovation Fund.
This paper will present the approach Space Forge is taking to develop these materials for terrestrial use, the drivers for such materials, and the challenges associated both in terms of business model and technology adoption and integration. | |
Microwave and Millimetre-Wave MMICs for Space and Defence Applications | |
| Jim Mayock | |
| VIPER RF | |
A set of microwave and millimetre-wave MMIC design examples will be presented based on GaAs, GaN and SiGe technologies. The MMICs have been designed for defence and space applications and cover operation from C-Band to D-Band. The designs to be presented will include a single-chip front end for space-based SAR applications, operating at C-Band with 40W of pulsed TX output power and PAE levels greater than 40% and an RX NF of 2.5dB, using a European 0.25um GaN-on-SiC technology. A Ka-Band chipset for low earth orbit downlinks for earth observation applications will be presented. The four-chip solution offers up-conversion, gain control and high-power amplification, with a peak output power of approximately 13W at Ka-Band. The chipset uses both European GaAs and GaN-on-SiC technologies. Several design examples of production devices at X-Band using cost-effective GaAs technologies including high power amplifiers and low-noise amplifiers will be presented. Finally, a set of V-Band, W-Band and D-Band MMICs which are under development will be presented. Low-noise amplifiers with NF levels of 2dB at W-Band have been developed using a GaAs mHEMT technology will be discussed. A set of power amplifiers using GaN-on-Si and SiGe technologies will be outlined. | |
Release of 0.25µm GaN MMIC PDK Strengthens Capabilities for the UK Defence Sector | |
| Jacek Gryglewicz | |
| INEX | |
As global demand for advanced connectivity increases across telecommunications, space, defence, and commercial sectors, the need for high-performance RF chips to power next-generation antenna systems is growing. To address this challenge, the UK requires a sovereign GaN foundry to meet increasing demand for RF components. At present, engineers are focused on developing solutions for large-scale antenna systems with integrated single-chip gallium nitride (GaN) front-ends driven by specialized driver chips. However, many UK defence contractors and design teams face barriers due to the lack of domestic GaN manufacturing capabilities, relying on international foundries that present concerns regarding intellectual property (IP) protection, competition, and export restrictions.
INEX Microtechnology Ltd. (INEX) has addressed these issues by pioneering the development of a secure, UK-based GaN technology supply chain. The IG25 process, based on the 0.25µm GaN-on-SiC, is specifically designed to provide reliable and high-performance solutions for applications spanning S-band to lower Ku-band frequencies. This paper highlights the advancements made in IG25 technology, offering performance metrics across a variety of frequency bands. Additionally, it provides an overview of the new process design kit (PDK) developed for seamless integration into Keysight’s Advanced Design System (ADS), facilitating the design and development of next-generation communication and defence systems. | |
The April meeting is sponsored by Castle Microwave.
Contributions are invited with an emphasis on RF and microwave design, research, testing and associated subjects. An oral presentation will be made at the meeting and a written paper will be required for publication in the society digest, which is distributed to delegates at the meeting. Prospective speakers are requested to submit a title and a short abstract to the technical coordinator (see above) as soon as possible.
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