Issue link: https://resources.system-analysis.cadence.com/i/1355140
Anritsu and Cadence Cadence is a pivotal leader in electronic design and computational expertise, using its Intelligent System Design strategy to turn design concepts into reality. Cadence customers are the world's most creative and innovative companies, delivering extraordinary electronic products from chips to boards to systems for the most dynamic market applications. www.cadence.com © 2021 Cadence Design Systems, Inc. All rights reserved worldwide. Cadence, the Cadence logo, and the other Cadence marks found at www.cadence.com/go/trademarks are trademarks or registered trademarks of Cadence Design Systems, Inc. All other trademarks are the property of their respective owners. 14265 02/21 DB/SA/SS-ATSU/PDF The time it takes to figure out how to do something with Microwave Office is far less than other circuit simulators on the market. It is the only circuit simulator Anritsu owns and uses. Jon Martens and Tom Roberts, Anritsu The EM model of the entire G-band tripler is shown in Figure 3. Figure 3: Complete 3DEM model of the G-band tripler Summary The design and development of a zero-bias, extended G-band planar frequency tripler was successfully accom- plished using AWR Microwave Office software, which enabled the designers to bring in n-port models created from other EDA products. The ability to quickly run the robust harmonic balance simulation engine and be fairly confident of solution convergence was an immense advantage in terms of cutting design time, as was the ease of plotting and displaying harmonic output power and conversion and return loss data. The ability to assign variables to model parameters was also very helpful. The quick and knowl- edgeable customer/technical support further helped the engineers streamline the design effort. The Solution The difficulty in meeting the input drive and unwanted harmonic suppression requirements for the DHG motivated Anritsu designers to develop an extended planar frequency tripler covering the entire G-band (140-220 GHz). Modeling the structure using a 3D simulator and extracting an accurate representation of the 6-port model was critical. The engineers chose Cadence AWR Design Environment software for this exacting design challenge. Figure 2 shows the tripler block diagram designed in the software. Figure 2: G-band planar frequency tripler design in the software The design uses two commercially available discrete Schottky anti-parallel varistor diodes on either side of the main line. An 80GHz stepped-impedance resonator (SIR) low-pass filter (LPF) reflects harmonics of the input signal and prevents all generated harmonics originating from the anti-parallel diode pairs from being absorbed back into the input. A 130GHz substrate integrated waveguide (SIW) high-pass filter (HPF) passes the X3 harmonic, reflects the fundamental, and partially reflects the unbalanced X2 harmonic. It was expected that the X5 harmonic would be at least 10dBc down from the third harmonic aided by losses at the output. When the model was brought into the AWR Microwave Office ® circuit design software, the n-port representation of the 3D model allowed the Schottky diode models to be placed at their prescribed locations represented as discrete elements in the circuit model.