Design and analysis of a 70-ps SiGe differential RF switch

This paper presents the design and analysis of an SiGe high isolation single-pole double-throw (SPDT) differential absorptive switch at 24 GHz for pulsed ultra-wideband applications. Sub-100-ps envelope rise times are achieved through the use of differential current steering. The SPDT results in 1.9 dB of gain in the passband and an isolation of 35 dB while remaining matched at its ports (absorptive). The measured rise time of the RF envelope is 70 ps using a transistor with an f/sub T/ of 80 GHz and agrees with both the simulated and analytically determined values.     

A novel parametric-effect MEMS amplifier

This paper presents the theory and measurements of a mechanical parametric-effect amplifier with a 200-kHz input signal and a 1.84-MHz output signal. The device used is a MEMS time-varying capacitor which is composed of an array of low-stress metallized silicon-nitride diaphragms, and is pumped by a large-signal voltage at 1.64 MHz. This induces a large change in the capacitance, and results in parametric amplification of an input signal at 200 kHz. The parametric amplifier capacitance is 500 pF, resulting in an output impedance of 140 Ω. A higher impedance can also be achieved with a lower capacitance. To our knowledge, this device is the first-ever MEMS mechanical up-converter parametric-effect amplifier developed with an up-conversion ratio of 9:1. The measurements agree very well with theory, including the effect the series resistance and the and of the MEMS time-varying capacitor. The application areas are in amplifiers which operate at very high temperatures (200°C-600°C), under high particle bombardment (nuclear applications), in non-semiconductor-based amplification, and in low-noise systems, since parametric amplifiers do not suffer from thermal, shot, or 1/f noise problems     

Miniature Four-Way and Two-Way 24 GHz Wilkinson Power Dividers in 0.13 μm CMOS

This letter presents 24 GHz four-way and two-way miniature Wilkinson power dividers (PDs) in a standard CMOS technology. The chip area is significantly reduced using a lumped-element design, and the effective areas of four-way and two-way Wilkinson dividers are 0.33 times 0.33 mm² and 0.12 times 0.29 mm², respectively. The four-way Wilkinson divider results in an insertion loss <2.4 dB, an input/output return loss better 15.5 dB, and a port-to-port isolation >24.7 dB from 22 to 26 GHz. The two-way Wilkinson divider results in an insertion loss <1.4 dB, an input/output return loss better 8.9 dB, and a port-to-port isolation >14.8 dB from 22 to 26 GHz. To the author's knowledge, this is the first demonstration of 24 GHz four-way Wilkinson PD in a standard CMOS technology.     

0.13-μm CMOS Phase Shifters for X-, Ku-, and K-Band Phased Arrays

Two 4-bit active phase shifters integrated with all digital control circuitry in 0.13-mum RF CMOS technology are developed for X- and Ku-band (8-18 GHz) and K-band (18-26 GHz) phased arrays, respectively. The active digital phase shifters synthesize the required phase using a phase interpolation process by adding quadrature-phased input signals. The designs are based on a resonance-based quadrature all-pass filter for quadrature signaling with minimum loss and wide operation bandwidth. Both phase shifters can change phases with less than about 2 dB of RMS amplitude imbalance for all phase states through an associated DAC control. For the X- and Ku-band phase shifter, the RMS phase error is less than 10^o over the entire 5-18 GHz range. The average insertion loss ranges from to at 5-20 GHz. The input for all 4-bit phase states is typically at -5.4 plusmn1.3 GHz in the X- and Ku-band phase shifter. The K-band phase shifter exhibits 6.5-13 of RMS phase error at 15-26 GHz. The average insertion loss is from 4.6 to at 15-26 GHz. The input of the K-band phase shifter is at 24 GHz. For both phase shifters, the core size excluding all the pads and the output 50 Omega matching circuits, inserted for measurement purpose only, is very small, 0.33times0.43 mm² . The total current consumption is 5.8 mA in the X- and Ku-band phase shifter and 7.8 mA in the K-band phase shifter, from a 1.5 V supply voltage.     

A 25–75-MHz RF MEMS Tunable Filter

This paper presents a state-of-the-art discrete RF microelectromechanical systems (MEMS) tunable filter designed for 25-75-MHz operation. This paper also presents an enhanced model of the RF MEMS switch, which is used for accurate prediction of the tunable filter response. The two-pole lumped-element filter is based on digital capacitor banks with on-chip metal-contact RF MEMS switches and lumped inductors, and results in a tuning range of 3:1 with fine frequency resolution, and a return loss better than 13 dB for the entire tuning range. The relative bandwidth of the filter is 4 plusmn 1% over the tuning range and the insertion loss is 3-5 dB, limited mostly by the inductor Q and the switch loss. The IIP₃ measurements prove that tunable filters with metal-contact series RF MEMS switches show extremely linear behavior (IIP₃ > 68 dBm).     

A 24 GHz 6-Bit CMOS Phased-Array Receiver

This letter presents a 24 GHz 6 b phased-array receiver implemented in 0.13 mum CMOS. This design is based on a novel active vector generator that results in wideband quasi-quadrature vectors, which are used to synthesize the desired phase response. The active phase shifter has measured rms gain and phase errors of <0.5 dB and < 2.8deg at 23-24.4 GHz, resulting in a 6 b resolution. The phased-array receiver has a gain of 14 dB, a NF of 6 dB, a 3-dB gain bandwidth of 4.7 GHz and wideband input and output match. The chip consumes 30 mA from a 1.5 V supply with dimensions of 0.66 times 1.25 mm² including pads (0.5 times 1 mm² without pads).     

A CMOS K-Band Quadrature Generator

This letter presents a K-band quadrature signal generator in a standard 0.13 mu m CMOS process. The quadrature generator operates from 18 to 21 GHz. A maximum output power of -3.7 dBm (per I or Q channel) is achieved, and the down converted signal suppression is >25 dB at the operating bandwidth. A measured sideband rejection ratio >30 dB is achieved from 19 to 21 GHz, with a peak of >40 dB at 19.5-20.5 GHz. The current consumption of the quadrature generator is 49-54 mA from a 2-2.5 V supply with an effective chip area of 0.51times 0.44 mm² . To the author's knowledge, this is the first demonstration of a K-band quadrature signal generator with high spectral purity and quadrature accuracy.     

$Ka$-Band Low-Loss and High-Isolation Switch Design in 0.13-$mu{hbox {m}}$ CMOS

This paper presents designs and measurements of Ka-band single-pole single-throw (SPST) and single-pole double-throw (SPDT) 0.13-CMOS switches. Designs based on series and shunt switches on low and high substrate resistance networks are presented. It is found that the shunt switch and the series switch with a high substrate resistance network have a lower insertion loss than a standard designs. The shunt SPST switch shows an insertion loss of 1.0 dB and an isolation of 26 dB at >35 GHz. The series SPDT switch with a high substrate resistance network shows excellent performance with 2.2-dB insertion loss and isolation at 35 GHz, and this is achieved using two parallel resonant networks. The series-shunt SPDT switch using deep n-well nMOS transistors for a high substrate resistance network results in an insertion loss and isolation of 2.6 and 27 dB, respectively, at 35 GHz. For series switches, the input 1-dB compression point (1P₁) can be significantly increased to with the use of a high substrate resistance design. In contrast, of shunt switches is limited by the self-biasing effect to 12 dBm independent of the substrate resistance network. The paper shows that, with good design, several 0.13- CMOS designs can be used for state-of-the-art switches at 26-40 GHz.     

Millimeter-wave integrated-horn antennas. I. Theory

The far-field pattern and input impedance of a dipole-fed horn antenna in a ground plane are calculated using full-wave analysis. The solution is based on the numerical evaluation of the pertinent Green's function for the horn structure and the application of the method of moments. The convergence characteristics of the full-wave analysis method are investigated, along the the resonant properties of the strip-dipole and the corresponding behavior of the far-field patterns     

Millimeter-wave integrated-horn antenna. II. Experiment

For pt.I see ibid., vol.39, no.11, p.1575-81 (1991). The impedance and radiation patterns of a dipole-fed horn antenna in a ground plane are experimentally investigated at microwave and millimeter-wave frequencies. The agreement with the full-wave analysis technique presented in part I is good. The results indicate that for a 70° flare-angle horn, horn apertures from 1.0 λ-square to 1.5 λ-square with dipole positions between 0.36 and 0.55 λ yield good radiation patterns with a gain of 10-13 dB a cross-polarization level lower than -20 dB, and resonant dipole impedances between 40 Ω and 120 Ω. It is also found that the impedance measurements can be safely used for 2-D horn arrays, but the radiation patterns differ because of the Floquet modes associated with the array environment. The integrated horn antenna is a high-efficiency antenna suitable for applications in millimeter-wave imaging systems, remote-sensing, and radioastronomy