In this work we assess the feasibility of fabricating a matrix of antennas for the millimeter (mm)-wave band using the “Multi Chip Module – Deposited (MCM-D)” process. The main focus of the design is to minimize the cross coupling between the antennas fabricated on the common substrate. We investigate the use of a virtual cavity formed by metalized vias in order to reduce the cross coupling to the neighboring cells. The radiation efficiency is analyzed in detail, and experimental results of a 2 × 2 array are presented.

A systematic comparison between several pairs of contact materials based on an innovative methodology early developed at NOVA MEMS is hereby presented. The technique exploits a commercial nanoindenter coupled with electrical measurements, and test vehicles specially designed to investigate the underlying physics driving the surface-related failure modes. The study provides a comprehensive understanding of micro-contact behavior with respect to the impact of low-to-medium levels of electrical current. The decrease of the contact resistance, when the contact force increases, is measured for contact pairs of soft material (Au/Au contact), harder materials (Ru/Ru and Rh/Rh contacts), and mixed configuration (Au/Ru and Au/Ni contacts). The contact temperatures have been calculated and compared with the theoretical values of softening temperature for each couple of contact materials. No softening behavior has been observed for mixed contact at the theoretical softening temperature of both materials. The enhanced resilience of the bimetallic contacts Au/Ru and Au/Ni is demonstrated.

Two different topologies of radio frequency micro-electro-mechanical system (RF MEMS) series ohmic switches (cantilever and clamped–clamped beams) in coplanar waveguide (CPW) configuration have been characterized by means of DC, environmental, and RF measurements. In particular, on-wafer checks have been followed by RF test after vibration, thermal shocks, and temperature cycles. The devices have been manufactured on high resistivity silicon substrates, as building blocks to be implemented in different single-pole 4-throw (SP4 T), double-pole double-throw (DPDT) configurations, and then integrated in Low Temperature Co-fired Ceramics (LTCC) technology for the realization of large-order Clos 3D networks.

In evaluating the potential of a given integrated-circuit technology, the negative conductance approach is used to estimate a maximum frequency limit for the ability of Heterojunction Bipolar Transistor (HBT) cross-coupled architecture to function as an oscillator at high frequencies. In this paper, the simple low-frequency estimation of the negative conductance, commonly used in the literature, is extended by deriving a new expression that takes into account the HBT parasitics. An expression for the frequency at which the negative conductance of the circuit crosses zero is given, which gives maximum frequency of oscillation for an ideal tank (no tank losses). In addition, the effect of the feedback capacitor, which is commonly added for direct current (DC) decoupling and boosting the negative conductance, is analyzed and new insight on the choice of the value of this capacitance is introduced. The results were proven by simulations using SiGe HBT transistors with an ft of 190 GHz.

The design of a 61.44 GHz integrated Phase-locked loop (PLL) on a 180 GHz BiCMOS technology is presented. The PLL was optimized for a very fast settling time of 4 µs as required by the system specifications. Because the receiver is using a carrier recovery circuit that can follow the slow changes of the carrier such as phase noise, the sensitivity of the bit error rate to phase noise at the receiver end is very low. As a result, to achieve the required dynamic behavior, the phase noise performance could be sacrificed and the loop bandwidth was increased until the needed settling time was achieved, while taking the suppression of the reference spurs into consideration. Capacitor multiplication was used to enable the integration of the loop filter (LF) on chip and the effect of the capacitor multiplier on the total PLL phase noise performance was quantified and evaluated. In addition, a very close matching between the measured and simulated phase noise of the system was achieved. The PLL consumes a power of 200 mW from 2 and 3 V supply voltages, while delivering a differential output power of −7 dBm, sufficient to drive the following I/Q modulator without additional amplification.

A 77-GHz–directional folded dipole antenna integrated in an embedded wafer level ball grid array package is presented. For the characterization of the antenna, a frequency multiplier is embedded, which scales the 4.25-GHz input signal up to 76.5 GHz and allows the use of a commercial signal source. The antenna structure is manufactured at the metallic layer, in the fan-out area of the package, and is directly connected to the monolithically integrated transceiver. The gain of the antenna is about 7 dBi, measured over a large bandwidth of about 8 GHz. The combination of the frequency multiplier with a 77-GHz transceiver and the on-package antenna is a promising approach for a system-in-package to future radar modules for automotive radar applications. Such a module avoids 77-GHz transitions to the printed circuit board and hence simplifies the design and manufacturing of the radar sensor significantly.

A 15–32 GHz miniature single-balanced gate mixer is proposed and analyzed. It achieves a smaller chip area with acceptable conversion gain and port-to-port isolation. In addition, the design procedure is described in detail. This mixer, fabricated in 90 nm digital CMOS technology, demonstrates a measured conversion loss of 1 dB and higher than 30 dB RF-to-LO port isolation from 17 to 32 GHz, at a local oscillator (LO) driver power of −4.3 dBm. The total dc power consumption is only 6 mW from a 1.2 V supply, including output buffer. The low dc power consumption and LO driver power reduce the power budget, and the proposed miniature rat-race hybrid facilitates integration in a receiver.

A simple and efficient numerical inversion Laplace transform (NILT) algorithm is implemented in MATLAB environment based on the quotient difference method to solve the problem of electromagnetic (EM) field coupling to lossy or lossless multi-conductor transmission lines (MTL) illuminated by an EM incident field. Two major points are treated in this work for the lossy MTL system excited by an incident EM field; the first one is the optimum equivalent circuit taking into consideration the different physical concepts based on the transmission line theory and the second point deals with the choice and implementation of the numerical method for less computing time and for efficient results. In this paper, the effect of the EM coupling is treated and it is based on the superposition effect of each distributed voltage current sources using the NILT numerical method. Results of the near end and far end voltages and currents for an MTL system are presented and displayed for two types of microwave (MW) structures in the time domain for the case of a plane wave excitation. It has been shown that a non-homogeneous MW structure or multilayered system with a specific choice of the dielectric constant has an advantage for less transient EM coupling due to the external EM field.

The mm-wave as well as avalanche noise properties of IMPATT diode at D-band are efficiently estimated, with different poly-types of silicon carbide (SiC) and GaN as base materials, using advanced computer simulation techniques developed by the authors. The breakdown voltage of 4H-SiC (180 V) is more than the same for 6H-SiC, ZB- and Wz-GaN-based diode of 170,158, and 160 V, respectively. Similarly, the efficiency (14.7%) is also high in the case of 4H-SiC as compared with 6H-SiC and GaN-based diode. The study indicates that 4H-SiC IMPATT diode is capable of generating high RF power of about 8.38 W as compared with GaN IMPATT diode due to high breakdown voltage and negative resistance for the same frequency of operation. It is also observed that Wz-GaN exhibits better noise behavior 7.4 × 10−16 V2 s than SiC (5.16 × 10−15 V2 s) for IMPATT operation at 140 GHz. A comparison between the power output and noise from both the device reveals that Wz-GaN would be a suitable base material for high-power application of IMPATT diode with moderate noise.