A 76-Gbit/s 265-GHz CMOS receiver (RX) modularized with a WR-3.4 waveguide interface is presented. It is a mixer-first RX fabricated using a 40-nm CMOS technology. The primary design focus is simplicity and the resulting low noise and loss and high conversion gain (CG). To allow for both on-wafer and packaged measurements, ON-chip transmission lines are designed such that their characteristics are relatively insensitive to the presence or absence of adhesive covering the chip. The RX chip is flip-chip-mounted on a multilayer printed circuit board (PCB). Built into the PCB is a waveguide transition using double-resonant stacked patches for wideband operation. The CMOS RX module achieves the highest wireless data rate of 76 Gbit/s with 16 QAM, which is comparable to 80 Gbit/s reported previously for a CMOS RX with on-wafer probing measurement.

Signal flow graph (SFG) representation of small- signal responses of nonlinear microwave circuits around a large-signal operating point is developed using the X-parameters. It is shown that, unlike the SFGs for linear circuits, negative-frequency nodes need to be included explicitly. The development elucidates the circuit-operational meaning of the elusive T-type small-signal X-parameters, which represent interaction between positive- and negative-frequency components. As an application example, such an SFG is used to derive a closed-form expression of the output power of a power amplifier as a function of the load reflection coefficient. It is then used to plot approximate load-pull power contours. The result is consistent with and more general than the expression of the optimum load reflection coefficient derived analytically by Root et al. (EuMIC 2017). SFGs provide a systematic means to derive closed-form expressions in terms of X-parameters and to gain illuminating insights into the workings of weakly nonlinear circuits.

No abstract

<p>Signal flow graph (SFG) representation of small-signal responses of nonlinear microwave circuits around a large-signal operating point is developed using the X-parameters. It is shown that, unlike the SFGs for linear circuits, negative-frequency nodes need to be included explicitly. The development elucidates the circuit-operational meaning of the elusive T-type small-signal X-parameters, which represent interaction between positive- and negative-frequency components. As an example, such an SFG is used to derive a closed-form expression of the output power of an amplifier as a function of the load reflection coefficient. It is then used to plot approximate load-pull power contours. The result is consistent with the expressions of the optimum load reflection coefficient derived by Root et al. (EuMIC 2017) and of power contours derived by Peláez-Pérez et al. (TMTT 2013). SFGs provide an alternative systematic means to derive closed-form expressions in terms of X-parameters and to gain illuminating insights into the workings of weakly nonlinear circuits. </p>

Signal flow graph (SFG) representation of small- signal responses of nonlinear microwave circuits around a large-signal operating point is developed using the X-parameters. It is shown that, unlike the SFGs for linear circuits, negative-frequency nodes need to be included explicitly. The development elucidates the circuit-operational meaning of the elusive T-type small-signal X-parameters, which represent interaction between positive- and negative-frequency components. As an application example, such an SFG is used to derive a closed-form expression of the output power of a power amplifier as a function of the load reflection coefficient. It is then used to plot approximate load-pull power contours. The result is consistent with and more general than the expression of the optimum load reflection coefficient derived analytically by Root et al. (EuMIC 2017). SFGs provide a systematic means to derive closed-form expressions in terms of X-parameters and to gain illuminating insights into the workings of weakly nonlinear circuits.