71-76GHz Low Noise Amplifier

A state-of-the-art low noise amplifier operating from 71GHz to 76GHz using a commercial GaAs MHEMT technology has been developed . The gain of the three-stage amplifier was measured to be 24dB, The noise figure of the LNA MMIC integrated in a WR12 waveguide module was measured to be 2.1dB-2.3dB and with return losses of approximately -13dB. The part is comparable to the best in class at W-Band

250W 2.45 GHz PA for moon based application

Viper RF worked alongside the Open University on a project to deliver a self contained RF generator module capable of supplying 250W continuous wave. Operating at 2.45 GHz into an aggressive load, the module comprised of a heating chamber filled with Regolith simulant. The longer term goal of the program is to use the module to melt lunar ice and soil to produce 3D printable building materials, extract water, oxygen and hydrogen from the natural resources on the surface of the moon. The demonstrated unit was manufactured with OTS components and contained a frequency generation circuit, RF power amplifiers as well as power supply hardware. The module was successfully demonstrated to melt the Regolith simulant and results presented to the OU and UK Space Agency.

LNA downconverter for MASER clock system

Viper RF worked alongside Nascent Semiconductor to create a room temperature miniaturised MASER clock unit. For use in positioning, navigation and timing systems (PNT) Viper RF produced the LNA and near zero downconverter module which included frequency generation functionality to produce a stable Local Oscillator signal integrated with an analogue to digital converter to form a locked reference clock. The key drivers of the design were high gain (>100dB) low noise figure (<1.5 dB), high reverse isolation and down conversion to near zero (10s of kHz). All PCBAs and metal work were designed in house. Modules were delivered for MASER integration using COTS components and were later updated with custom Viper RF MMICs.

A Compact K-Band High Data Rate Upconverter / Solid State Power Amplifier

Viper RF worked to develop an engineering model of a Ka-Band transmitter downlink module for LEO satellites on an ESA Contract. The module consists of a custom MMIC chipset, LO circuit module, RF filtering and associated module control electronics. The MMIC chipset consists of an IF attenuator, up-converter, driver MPA and HPA. The HPA exhibits a peak output power of approximately 41dBm with an associated PAE of 25% in the 25.5-27GHz band. The MPA has a small-signal gain of greater than 27dB with an output power > 31dBm. The up-converter MMIC has a conversion gain of approximately 25dB with compliant spurious performance and the attenuator MMIC provides 6-bit control. The MMICs are mounted onto a 4-layer RF substrate and copper inserts provide a low thermal resistance between the package and module baseplate. The output from the MMIC PCA feeds a PCBWR34 transition mounted underneath the PCA, this in turn feeds the waveguide filter. The DC power consumption is 55W from 28V.

W-band GaAs LNA chip set for space telecommunications

Viper RF worked to design and characterise two cutting edge low noise amplifiers from 81GHz to 86GHz using the D007IH GaAs metamorphic HEMT (mHEMT) technology from MACOM.

Viper RF ARMMS Conference Papers

Viper RF was the coordinator for the April 2025 ARMMS conference where the company was involved in the presentation of three papers. The first paper presented a set of microwave and millimetre-wave MMIC designs based on GaAs, GaN, and SiGe technologies. The second paper presented two targeted HPA designs in the V-Band and W-Band. The third paper presented the development of a MASER based timing system for deployment outside of a laboratory setting.

Frequency converter & amplifier MMICs for LEO satellite constellation

From the receipt of a design brief in 2016, VIPER RF performed custom designs of multiple MMICs.

Supply of packaged MMICs for a satcomm application commenced in 2018 with first VIPER RF parts launched into Space in 2019. Since then, over 10,000 MMIC have been supplied into this mega-constellation application

Development of a microwave source for spacecraft propulsion system

VIPER RF is participating in a consortium led by AVS-UK developing an innovative system for the electric propulsion of spacecraft.

Overall goals of the UK Space Agency National Space Technology Programme (NSTP) funded AQUAJET|NJET|XJET project include demonstrating improved thruster performance with xenon, scaling testing up to the 200-400 W power range, achieving stable operation with water and ammonia, and testing of a custom built solid state microwave generator in vacuum. VIPER RF have design and manufactured a compact and high-efficiency microwave generator delivering approximately 200W of CW power at S-Band in vacuum.

Development of D-band MMICs for next generation 5G/6G point-to-point radio links

A MMIC chipset has been developed for next generation 5G/6G point-to-point communications. A highly integrated transmitter and receiver operating up to 140GHz has been developed. Each part has integrated LO multiplication, IF gain control, mixing, filtering and D-Band gain functionality on a single-chip. The parts are based on a high performance 0.1um D-mode GaAs pHEMT technology. The MMICs have been successfully integrated into a 300m D-band radio link.

Robust 5-18GHz GaN Low Noise Amplifier

A state-of-the art robust GaN limiting-LNA for applications including next generation Electronic Warfare T/R modules has been developed. The circuit relies on a balanced design technique and exploits an innovative biasing circuit scheme to control the output power compression characteristic. The MMICs operates across the 5 to 18 GHz band, with an average noise figure of 3.5 dB and an associated gain of 13 dB; output power is clamped around 13 dBm up to 4W of input excitation, while guaranteeing a minimum OP1 dB of 10 dBm. VIPER RF has supplied several thousands of these MMICs to a world-leading defence client. The part compliments the newly released product range of GaAs LNAs operating from C-Band to Ka-Band.

Phased array transmitter unit for next generation 5G Smart Cities communication systems

An Innovate UK funded project with a Turkish system integrator on the development of a multi-channel transmitter for 5G phased array radio systems.

Several MMIC chips developed include a 28GHz amplitude and phase control part (six bit phase and amplitude control) and Doherty amplifiers. The chips were configured in a SIP with integrated antenna to provide a four channel transmitter solution for 5G applications.

71-76GHz Low Noise Amplifier

A state-of-the-art low noise amplifier operating from 71GHz to 76GHz using a commercial GaAs MHEMT technology has been developed . The gain of the three-stage amplifier was measured to be 24dB, The noise figure of the LNA MMIC integrated in a WR12 waveguide module was measured to be 2.1dB-2.3dB and with return losses of approximately -13dB. The part is comparable to the best in class at W-Band

26-GHz data downlink and RF beacon for LEO in orbit demonstrator satellite

The development of a complete (on board, on ground) Low Earth Orbit system solution to allow Ka-Band propagation measurements and Variable Coding and Modulation (VCM) demonstration through multiple ground stations. It provides a step towards the adoption of the 25.5 to 27GHz band for Earth Observation (EO) downlink from LEO.

This paper contains key findings of an ongoing study conducted by SSTL and VIPER RF for ESA with the ultimate goal of initiating a number of on board hardware developments and rapidly deploying this technology on small satellite platforms.

Highly Integrated GaAs and GaN MMICs

The development of a number of GaN and GaAs MMIC high power and highly integrated solutions covering a range of space, commercial and defense applications were presented. Reported designs were based on developments from C-Band up to W-band frequencies where focus has been placed on maintaining and maximising parameters such as power added efficiency (PAE), output power, cost and high levels of integration. Activities to de-risk the development of highly integrated parts such as hybrid prototyping and active model verification were discussed. The trade-offs between performances of GaAs and GaN MMICs were considered and limitations in terms of output power performance, PAE and levels of integration were presented

Patch Antenna Design through the application of genetic algorithms

Viper RF sponsored a PHD student at Durham University to investigate THz antenna design using a bespoke genetic algorithm. A patch antenna designed using this technique was found to have a mean improvement of 7.58 dB on a reference patch between 0.1 THz and 5.0 THz.

Ka band up convertor module

Viper RF designed a four MMIC chipset on GaAs and GaN technologies from Unite Monolithic Semiconductors. The DCA and the upconverter was designed on GaAs technology while the medium power amplifier and the high power amplifier was designed on GaN-on-SiC (GH15). The IF frequency was from 7.8 to 8.6GHz while the LO frequency was fixed at 17.05 and 17.4GHz. The output power was measured to be greater than 40.5dBm.

An Asymmetrical Single-stage GaN MMIC DPA at 25 GHz

An asymmetric single-stage Doherty power amplifier (DPA) in MMIC form using OMMIC GaN transistors operating at 25 GHz. The DPA implements a dynamic input power division technique in contrast with the more conventional fixed input power division.