90 GHz CMOS Phased-Array Transmitter Integrated on LTCC

This paper presents the design of a 90 GHz phased-array transmitter front end on low-temperature co-fired ceramic (LTCC) technology. The monolithic microwave integrated circuit components have been fabricated by the CMOS technology and flip chipped on the LTCC to realize the transmitter front end. The dc and differential hybrid IF signals are provided to the flip-chipped components through the bias and IF lines designed on the LTCC. An 1 × 4 patch antenna array has been designed for the transmitter and fabricated on the LTCC. The dc and IF signal pads on the LTCC were soldered to the designed printed circuit board pads for measurements. The measurement results show that by using a receiver horn antenna, the maximum received power at 92 GHz is -37.3 dBm at a communication distance of 1 m. The transmitter is capable of providing ±25° beam steering with respect to boresight and 20° half-power beamwidth at 90 GHz. The total power consumption of the transmitter front end is 656 mW.

I. Introduction

The increasing demand for multigigabit wireless data transfer and high-speed communication links has generated a great deal of interest in millimeter waves. Millimeter waves provide inherently a broad bandwidth which enables a high data rate transfer. Short-range applications such as near-field communications and wireless personal area networks are the good examples where millimeter and submillimeter waves could be employed [1], [2]. Millimeter-wave communication systems are currently being developed, for example, at 28, 38, and 60 GHz and -band (71–76 and 81–86 GHz) for both 5G access and backhaul systems [3]. Anticollision radar systems are also developed around 77 GHz [4].