A Wideband IF Receiver Module for Flexibly Scalable mmWave Beamforming Combining and Interference Cancellation

Abstract

Large-scale phased arrays need to combine weighted signals from multiple sub-arrays either in analog or in digital domain. Sub-arrays are preferably implemented modularly with integrated circuits placed next to the associated antennas. In order to enable flexible and scalable combining networks of several mmWave sub-arrays, this paper presents a wideband receiver module that provides the cartesian combining of beamforming weights for one sub-array at IF. Furthermore, it allows interference cancellation between subarrays or combining multiple sub-arrays. It also provides filtering before ADCs to support current and foreseeable 5G channel bandwidths up to 800MHz. The receiver is operating at 2-4GHz IF frequency range and has more than 400MHz baseband bandwidth, a noise-figure of 5.5dB,-6dBm 1dB compression point and +3dBm in-band IIP3. In addition, overthe-air measurements are performed, showing 26dB of interference cancellation between the sub-arrays. The prototype is implemented using 45nm CMOS PDSOI.

Origins and minimization of intermodulation distortion in a pseudo-differential CMOS beamforming receiver

“…Alternatively, as filtering consumes too much area, one can reduce the switch on resistance to minimize the v ds magnitude. For instance, Akbar et al [3] achieves this by employing LO bootstrapping to increase the gate drive.…”

“…Therefore, we consider three different bandwidths which include only the beat frequency (100 kHz), the carrier frequency (3 GHz), and the second harmonic band (6 GHz). The beat frequency is chosen arbitrarily, and as the main circuit in [3] supports a baseband bandwidth of over 400 MHz, it can also be pushed further. Results are presented in Table 1 assuming both opposite-phased (Diff) and in-phase (CM) inputs, and a third case where a 10% amplitude mismatch is introduced between the differential inputs.…”

“…Much interest has been devoted to analyzing the linear properties (gain, noise, beam pattern) of highly parallel systems, but studying their nonlinearity has been less frequent [1,2]. This paper focuses on the nonlinearity analysis of the circuit blocks in the 3 GHz IF section of a beamforming receiver architecture proposed in [2,3].…”

“…The LNA structure is chosen to be as simple as possible to keep the circuit compact and still give sufficient bandwidth. The circuit structures for analysis have been taken from [3], but due to limitations in technology access, the device characteristics and comparisons to simulations have been performed using a different IC process. Hence, the performance is not an exact match to [3].…”

Spatial Interference Reduction by Subarray Stacking in Large Two-Dimensional Antenna Arrays

“…The interference can also be cancelled over the subarray inputs/outputs by using different digital or analog cancellation techniques. Interbeam Interference Cancellation (IBIC) [42] is one of these methods to cancel beams over subarray inputs/outputs and hence over several directions. Precise cancellation by any of the digital (or analog) methods, however, requires precise amplitude and phase control because cancellation is very sensitive to errors.…”