Miniaturized and Process-Tolerant Ku-Band Power Dividers Using GaN on SiC

This paper presents two types of power dividers at Ku-band using GaN MMIC technology on a SiC substrate. The first divider (PD-I) is a miniaturized Wilkinson power divider whose transmission line arms are replaced with equivalent lumped circuit elements. The divider size is reduced while preserving the performance of the original Wilkinson power divider. In the second type of divider (PD-II), an improved isolation network design is implemented along with the miniaturization technique to improve the operational bandwidth and provide tolerance against variations in sheet resistivity. PD-I has a size of 0.06 ƛ × 0.1 λ. The measured center frequency is 14.1 GHz and the measured fractional bandwidth for 0.45 dB insertion loss and 20 dB isolation and return losses is 21.2 %. PD-II has tolerance to sheet resistivity variation up to ±30 % while occupying 0.19 ƛ x 0.1 ƛ chip area. The measured center frequency is 13.8 GHz and the measured fractional bandwidth for 1.0 dB insertion loss and 15 dB isolation and return losses is 61%. The results demonstrate that using the proposed divider topology wideband and low insertion loss operation can be achieved in a compact area with additional process tolerance.