A 10-bit active RF phase shifter for 5G wireless systems

Abstract

Abstract-This paper presents an active RF phase shifter with 10 bit control word targeted toward the upcoming 5G wireless systems. The circuit is designed and fabricated using 45 nm CMOS SOI technology. An IQ vector modulator (IQVM) topology is used which provides both amplitude and phase control. The design is programmable with exhaustive digital controls available for parameters like bias voltage, resonance frequency, and gain. The frequency of operation is tunable from 12.5 GHz to 15.7 GHz. The mean angular separation between phase points is 1.5 degree at optimum amplitude levels. The rms phase error over the operating band is as low as 0.8 degree. Active area occupied is 0.18 square millimeter. The total DC power consumed from 1 V supply is 75 mW.

A four channel phased array transmitter using an active RF phase shifter for 5G wireless systems

“…Two different methodologies were used to measure the phase shift provided by the fabricated devices. For the standalone IQVM [11], as both the input and output were at RF, vector signal measurements were done using Keysight PNA-X N5247A. However, in case of the phased array IC, as the input was at baseband and the output was at RF, direct vector measurements using a vector network analyzer was not possible.…”

“…Raw data showing all the 1024 different phase and amplitude points as provided by the standalone IQVM is shown in Fig. 12 [11]. It can be seen from Fig.…”

“…The IC implementation of a four channel phased array transmitter presented in this paper is based on our previous work on the IQVM [11] and with new results. Depending on the value of the resonance control word, it is possible to change the center frequency of the IQVM presented in [11] from 13.75 GHz to 14.45 GHz. Furthermore, it has an RF bandwidth of 2.5 GHz at a fixed resonance control word.…”

“…Positive side of the binary tree used for realizing the VCCS structure used in IQVM. Control bits are numbered from I 0 -I 3 and Q 0 -Q 3 for I and Q branch respectively[11]. Simplified schematic of the driver stage.…”

A 25 GHz Active Phase Shifter Using 10 bit Cartesian Control

“…There are multiple ways to make a phase shifter, by vector summing orthogonal signals with different weights using a cartesian [5]- [7] or polar [8] codebook, and by changing the properties of a transmission line [9], [10]. The benefit of the vector summing method is its small implementation size but at the cost of power consumption.…”