The QV Band High Power Hardware technology development project completed the design and proof of concept Engineering Models of a high power Isolator and a compact Output Multiplexer for use in the new 40 GHz QV band frequency range. The QV Band (37.5-42.5 GHz) will be taking on more of a Gateway role in upcoming communication satellites, and this project will develop to have high RF power and high reliability product designs ready to take up to 200 Watts of applied power.
The extremely small size of the WR22 products have difficult challenges due to the size limitations for manufacturing and assembly, as well as the very precise tolerances needed to get the best repeatable operation. Some internal components are expected to be well less than 1 mm in size, which will tax the fabrication and production processing.
There are no space qualified products currently available for use up to 200 Watts at QV Band, nor are there any proven effective multiplexing techniques for use at this 40 GHz, WR22 application.
The project aim is to develop full bandwidth product abilities, with up to 5 GHz operating bandwidth and centered on 40 GHz. The Isolator will be able to withstand a full 200 Watt incident signal, simultaneously with a fully shorted signal at the output, for an indefinite time period. The Output Multiplexer will be designed to withstand any incident signal at band center of any filter, at the operating band edge as well as at the full out of band frequencies. The Omux will explore the use of nontraditional multiplexing and filtering designs and techniques to help overcome the size and sensitivity difficulties at WR22 applications. The Omux will further develop a compact common port path to reduce the overall footprint versus traditional output multiplexers.
The end products anticipated to produce are an amplifier protection isolator, as well as a high power signal combining multiplexer where both can work in the QV frequency band of 37.5 to 42.5 GHz. The power per signal path is to be able to operate up to 200 Watts each. The protection isolator will be a signal circulating device also fitted with a high power termination to absorb the fault case, reflected energy. The output multiplexer will be a compact footprint, combining network for 4 individual bandpass channel filters, collecting the inputs of all the signals via a compact manifold technique into a single, common output path to supply the downlink path. To supplement the Omux signal integrity will be an output filter to reject the receive band at 50GHz.
The QV band Isolator is realized using a differential phase shifter assembly. This structure gives very stable RF performance abilities while also giving very good power handling abilities and margins. The Omux is a single piece, one sided assembly that maximizes the output multiplexer abilities for small signal as well as large signal performance and margins.
The project will be divided into 3 phases: firstly an initial exploratory design segment to review all possible technologies and down-select the best candidate performer. This initial phase is approximately 3 months.
The second phase scope completes a detailed design phase including 3D modelling, full supporting analysis and breadboarding to prove operation is possible. Phase 2 requires approx. 12 months to complete. The final phase taking roughly 9 months will fabricate, assemble, tune & test an Engineering Model of each design, to produce and test for all critical operating functions and to prove all critical operational characteristics.
The Technology Development project has completed all detailed design activities, has fabricated, assembled and environmentally tested all three major Engineering Models. The Isolator, Omux and LPF have undergone very detailed peak power analysis to find the margins to breakdown with a very high degree of confidence.