A 28 GHz SiGe QVCO and divider for an 81–86 GHz E-band beam steering transmitter PLL

Abstract

This paper presents a QVCO a 28 GHz SiGe PLL. It was designed in a S f T = 200 GHz. The PLL is intended to be used in an 81-86 GHz E-band transmitter. P implemented by programmable current inject filter. The simulations in Spectre use a layout ex parasitics for the QVCO and the frequency div Momentum model for the QVCO inductors implemented with four cascaded current-m blocks, for a reference frequency of 1.75 GHz. T parts of the PLL were represented Verilog-A or schematic models. The phase no equals -105 dBc/Hz at 1MHz offset, while at th divider standalone has an input referred -110 dBc/Hz. The phase control has been ver simulations showing a phase control sensitivity range exceeding 360°. With a supply of 1.5 V divider consumes 29 mA.

A 28 GHz SiGe PLL for an 81–86 GHz E-band beam steering transmitter and an I/Q phase imbalance detection and compensation circuit

“…The schematics of the QVCO core and architecture for I/Q phase error tuning [8,9], used both standalone, see Fig. 4, and in the PLL, see Fig.…”

“…The QVCO inductors, L VCO , are simulated and modeled using ADS Momentum. The design is identical to the QVCO presented in [8,9], except that the main varactor is 10 % smaller in the PLL design in order to increase the maximum oscillation frequency. Each part of the QVCO contains two phase error tuning blocks biased with control voltages V tune_p and V tune_n .…”

“…1, a 28 GHz QVCO is used to generate the 84 GHz TX carrier in two steps [3,8,9]. An architecture with a QVCO operating directly at the 84 GHz carrier frequency is not preferred due to stringent requirements on I/Q phase error for higher order QAM modulation [5][6][7].…”

“…Instead a 28 GHz I/Q mixer first up-converts the baseband signal. The 84 GHz TX signal is then created by mixing with the 56 GHz differential second harmonic present at the emitters of the cross coupled QVCO transistors [3,8,9]. This paper first describes the design and layout of circuit 1, a 28 GHz beam steering PLL, see Fig.…”

“…at 28 GHz, the Q-value of the custom made MOM capacitors exceeds that of the MIM capacitors provided by the SiGe technology [8]. Since the supply is 1.5 V and the process does not have any MOS devices it is difficult to design the logic blocks required for a conventional phase frequency detector using a charge pump [9,[12][13][14][15][16].…”