Abstract
In this paper, a 37-42.5GHz (N260 Band) 64 channel full-digital multi-beam array for 5G massive multiple input multiple output (MIMO) applications is developed. The multi-beam array is built on a time division duplexing (TDD) architecture in which the transmitter and receivers are independent and working separately to enable more flexible channel configuration and hardware distribution. The 64 antenna elements of the array are aligned in a way that 16 elements lie in the horizontal and 4 in the vertical direction to deliver higher beam resolution in the horizontal plane. By using cables of unequal lengths, the $16\times 4$ antenna elements are connected to a cluster of $8\times 8$ transmitters/receivers. The hardware design of the transmitters, receivers, antennas and other circuits is demonstrated, with excellent measured RF performance achieved. Furthermore, the calibration of the massive MIMO array is presented, and the influence of inequality of array feedlines on calibration accuracy in a wide bandwidth is analyzed and experimentally verified. Finally, experimental studies on single beam scanning, multiple concurrent beam generation and over-the-air (OTA) performance of the transmitting and receiving array have been done. Simulation and measurement results suggest that the array has an excellent beam-forming capability that supports beam steering and generation of multiple concurrent beams. The OTA test reveals that the array can provide high modulation and demodulation accuracy for communication.
Highlights
As the demand for high data rates in mobile communication increases, the concept of the fifth generation communication (5G) has been proposed [1]
In the transmitting path of the time division duplexing (TDD) architecture, the millimeter-wave transmitter front-end which contains 64 radio frequency (RF) channels up-converts the intermediate frequency (IF) signals to the Q-band RF signals ranging from 37GHz to 42.5GHz
For a 500MHz-wideband modulated signal centered at 40GHz, according to the analysis in [50], once the array is calibrated at the frequency of 40GHz, the maximum phase difference between antenna elements is reached at the edge frequencies of the lower and upper sidebands, which are 39.75GHz and 40.25GHz, respectively
Summary
As the demand for high data rates in mobile communication increases, the concept of the fifth generation communication (5G) has been proposed [1]. In the transmitting path of the TDD architecture, the millimeter-wave transmitter front-end which contains 64 RF channels up-converts the IF signals to the Q-band RF signals ranging from 37GHz to 42.5GHz. The Tx IF sub-system includes 64 IF modulators that modulate the 500MHz I/Q differential baseband signals to single-ended IF signals centered. Taking the antenna element gain GAnt of 7 dBi into account, the maximum EIRP of the transmitting array calculated from formula (1) is 47 dBm
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
