Couplers

This article describes the use of CST MICROWAVE STUDIO® in simulating and optimising a 10-way conical transmission line power combiner operating at X-band (6-14 GHz). Simulated and measured results are compared. Read full article..

This article concerns the design of a X-Band squintless horn antenna array consisting out of 96 radiating elements. The full design of the 2.4m antenna blank (including the simultaneous excitation of all 96 arms) has been performed within CST MICROWAVE STUDIO®. The simulated results have been in an excellent agreement with compact range measurements. Read full article..

J. Rodnizki, Soreq NRC The SARAF RFQ is a four rod RFQ, operating at a frequency of 176 MHz, designed to bunch and accelerate a 4 mA deuteron/proton beam from 20 keV/nucleon DC up to 1.5 MeV/nucleon CW. The electrodes voltage for accelerating deuterons is 65 kV, a field of 22 MV/m (1.6 Kilpatrick). The RFQ injected power is induced by a loop coupler. The power needed to achieve this voltage is 250 kW, distributed along the 3.80 m RFQ length. This constitutes a power density that is approximately 3 times larger than that achieved in other 4-rod RFQs. The RFQ tank is made of 35 mm thick stainless steel. Its inner surface is electroplated with Copper. At high power, local high surface currents in the RFQ might cause overheating which will lead to out-gassing and in turn to sparking, which will prevent the RFQ from reaching the desired operating power. Therefore, there is a vital need for a detailed RF simulation of the RFQ, in combination with heat transfer simulations, in order to determine a priori the areas that heat up uncontrollably at high power, and aid in the design of further cooling to circumvent these phenomena. These simulations should include the RFQ detailed structure and its water cooling system, which incorporates a total flow of 1000 liter/minute. We used CST MWS to simulate the RF currents and fields in a 3D detailed model of the SARAF RFQ, including its loop coupler. The correct eigenmode was reproduced and both Qe and Qo are consistent with the measured ones. Detailed results reproduced the experimental observation of several overheated regions in the RFQ, including the end flanges and the plungers. Further results predicted overheating at regions around the bottom of several ports in the RFQ tank, as shown in figure 1, which were subsequently measured and are now being fixed by additional cooling. Read full article..

CST MICROWAVE STUDIO® can be succesfully applied to optical problems as shown in this example of an optical ring coupler solved up to 250 THz. Read full article..

This article demonstrates a strong feature of CST STUDIO SUITE™: Co-Simulation of a hybrid mixer with CST MICROWAVE STUDIO® (CST MWS) and CST DESIGN STUDIO™ (CST DS). A full 3D model is simulated and matched to a network using the in-built circuit simulator. Measured results compare well to the simulated results. Read full article..