A 4-Element Digital Modulated Polar Phased-Array Transmitter With Phase Modulation Phase-Shifting

Abstract

A novel architecture of a digital modulated polar phased-array transmitter with phase modulation (PM) phase-shifting and feed-forward controlled dynamic matching (FFCDM) is presented in this article. Phase-shifting in a PM signal path is utilized in each element, which shares many components including a phase modulator, baseband, and IF components. The characteristics of the proposed architecture are analyzed. With a constant envelope of PM signals, the implicit nonlinearity of the phase shifter in this architecture has low impact on the linearity performance of a phased-array system. Meanwhile, low phase error can be achieved by high-resolution phase interpolation with the digital predistortion (DPD) technique. Efficiency for both saturated and 6-dB back-off power is enhanced by digital power amplifier (DPA) with FFCDM. As a proof of concept, a 3-7 GHz 4-element phased-array transmitter is designed and fabricated in 40-nm CMOS based on the proposed method. The measured root-mean-square (rms) phase error of 0.3 • , effective phase shifting resolution of 9-bit, and peak system efficiency of 38.2% are achieved. For 40 MHz 64-QAM modulation signal, it exhibits EVM of 5.38% and 5.37%, P out of 14.30 and 14.46 dBm, and PAPR of 7.08 and 6.97 at 3.5 and 5.2 GHz, respectively. The measured peak EIRP is 35.6 dBm with a unit antenna gain of 2.98 dBi at 5 GHz. The radiation patterns with 0 • , 15 • , 30 • , and 45 • steering are measured based on monopole antennas. Meanwhile, the array achieves <4.7% and <5.9% EVM for 64-QAM signals with bandwidths of 20 and 40 MHz, respectively.

Millimeter-Wave Quadrature Mixed-Mode Transmitter With Distributed Parasitic Canceling and LO Leakage Self-Suppression

“…The DPA operating at the switching mode features high efficiency. The high-efficiency DPAs are usually developed for sub-6 GHz in recent year [17], [18], [19], [20], [21], [22], [23], [24], [25], [26], [27], [28], [29], [30], [31], [32], [33], [34], [35], [36], [37], [38], [39]. The current-mode DPAs based on Class-E [24], [25] and inverse Class-D [26], [27] are reported with high efficiency.…”

A Self-Calibration SCPA With Storage Capacitor Array Supporting 64-/256-/1024-QAM

“…For high linearity, analog PAs, i.e., Class-A and Class-AB PAs, have been widely used with limited efficiency [4], [5], [6]. On the contrary, digital PAs have been widely investigated in recent years for their merits of high efficiency and flexibility of operation modes [7], [8], [9], [10], [11], [12], [13], [14], [15], [16], [17], [18], [19], [20], [21], [22], [23], [24], [25], [26], [27], [28], [29], [30], [31], [32]. The switching unit cells contribute to the high efficiency of digital PAs.…”

C‐band 180‐nm CMOS transmitter front‐end with a three‐stage power amplifier for phased array applications

“…High‐performance microwave transmitter (TX) front‐end is an essential component in phased array systems. Silicon CMOS TX front‐end research has become popular in recent decades, due to its low‐power consumption, high integration, and low cost 1–6 . However, for practical applications, the output power level, the linearity, and the efficiency of a silicon CMOS TX front‐end still need to be improved.…”

“…Silicon CMOS TX front-end research has become popular in recent decades, due to its low-power consumption, high integration, and low cost. [1][2][3][4][5][6] However, for practical applications, the output power level, the linearity, and the efficiency of a silicon CMOS TX front-end still need to be improved. The output power, the power efficiency, and the linearity of a TX front-end are mainly determined by its power amplifiers (PAs).…”