• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.3
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• pp.335-342
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• 2012

A high-isolation Ka-band WR-28 waveguide power combiner is designed and implemented using a resistive septum. The waveguide power combiner developed here is an E-plane T-junction type with a TaN resistive septum inserted in a slit of waveguide junction. The fabricated waveguide power combiner shows a return loss better than -20 dB and an insertion loss less than 0.1 dB. Also the measurement shows isolation levels of 20 dB or more almost all over the band and in particular 25 dB or more below 37 GHz. The amplitude and phase imbalance are measured to be less than 0.1 dB and $2.5^{\circ}$, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.2
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• pp.262-265
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• 2012

In this paper, a Ka-band 8 W power amplifier module with WR-28 waveguide input and output ports is implemented and measured using four 2 W power amplifier modules and 4:1 waveguide power combiners with high isolation of 25 dB at 35 GHz. The 2 W power amplifier modules are fabricated using waveguide-to-microstrip transitions and show output power of 32.5~33.3 dBm and power gain of 26.9~28.7 dB at 35 GHz. Four 2 W power amplifier modules are combined through 4:1 waveguide power combiners with resistive septum and the combined power shows 39.0 dBm(8 W) under 6 V drain bias and 39.6 dBm(9.1 W) under 6.5 V drain bias at 35 GHz.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.7
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• pp.791-799
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• 2008

In this paper, the electromagnetic modeling and network analysis are proposed for design of GTEM cell operating from DC to 18 GHz. 3D electromagnetic numerical analysis models composed of the coaxial mode-converter for the feeder of GTEM cell, 5 m expanded rectangular coaxial transmission line, and the resistive termination load for current and field transmitted from the feeder are developed. Equivalent network model of feeder, transmission line, and termination load in the GTEM cell is also proposed, so the return loss of GTEM cell is calculated using S-parameters using the electromagnetic numerical analysis. To verify the proposed design method, the GTEM cell is designed, constructed and tested, with its size of $5{\times}2.5{\times}1.7\;m$ and operating frequency of $DC{\sim}18\;GHz$.