Monolithic integrated millimeter-wave circuits based on silicon and SiGe are emerging as an attractive option in the field of millimeter-wave communications and millimeter-wave sensors. The combination of active devices with passive planar structures, including also antenna elements, allows single-chip realizations of complete millimeter-wave front-ends. This paper reviews the state-of-the-art silicon- and SiGe-based monolithic integrated millimeter-wave circuits. The technological background as well as active and nonlinear devices and passive circuit structures suitable for silicon- and SiGe-based monolithic integrated millimeter-wave circuits are discussed. Examples of such integrated circuits and first systems applications are also presented.

Si and SiGe millimeter-wave integrated circuits

This paper describes basic research carried out to design a microwave source module employing the concept of an active-integrated leaky-mode antenna. The novel active-antenna source module utilizes a microstrip as the radiating element while adopting uniplanar technology for the active circuit design. The microstrip is operated in the first higher order odd mode, which is a leaky mode, and excited by a proximity-coupled center-fed slotline on the same surface of the uniplanar microwave-integrated circuit. The measured performance of an X-band transmission-type injection-locked active-integrated antenna source module demonstrated that such a design approach was suitable for linear array integration for quasi-optical power combining. The harmonic-balance (HB) analysis of the proposed active-integrated antenna agrees with the measurements in both free-running frequency and power level. The measured radiation patterns of the active-integrated antenna also agree well with the theoretical predictions.

https://ir.nctu.edu.tw:443/bitstream/11536/897/1/A1996VZ13800017.pdf

Oscillator-type active-integrated antenna: the leaky-mode approach

A comprehensive description of a modular optoelectronic measurement system for the characterization of high-frequency microelectronic devices and circuits is presented. Depending on application, specific techniques to generate, synchronize to, and detect high-frequency electric signals are combined covering a frequency range of more than three orders of magnitudes from 2 to 4000 GHz. We discuss on-chip electric-pulse generation by freely positionable photoconductive probes and by direct optical excitation of active devices. Alternatively, for measurements with external, electronically generated signals, the system is laid out to lock onto periodic signals of arbitrary frequency employed as clock signal for the circuit under test. With respect to detection, the following approaches are discussed: sampling with freely positionable electrooptic and photoconductive probe tips, and truly (probe-tip-free) all-optical testing based on the field-dependent optical nonlinearity of the circuit's substrate material. The probes are characterized concerning time resolution, linearity, sensitivity, and invasiveness. We demonstrate with a number of examples that the combination of the various modules allows one to optimize the approach to a specific testing problem. Measurements of the linear and nonlinear behavior of active and passive devices as well as circuits are presented. The electric field, respectively potential, is measured locally (point measurements) or in its spatial distribution (field mapping) both in the near and far field.

Optoelectronic on-chip characterization of ultrafast electric devices: Measurement techniques and applications

The choice of a highly resistive substrate for silicon millimeter-wave integrated circuits (SIMMWIC) imposed by the requirement of low RF-substrate losses requires the adaptation of a CMOS process on float zone silicon (FZ). A comparison of n- and p-channel devices realized on high resistivity substrate (p-type, 5000 /spl Omega//spl middot/cm) and standard CMOS substrates (CZ, n-type, 4-6 /spl Omega//spl middot/cm) is given. Using careful process design, we obtained device characteristics on FZ-substrates that are closely similar to those on standard material, thus allowing direct transfer of existing circuit designs.

CMOS on FZ-high resistivity substrate for monolithic integration of SiGe-RF-circuitry and readout electronics

Rectifying antennas (rectennas) are realized on high-resistivity silicon substrates using silicon monolithic millimeter-wave integrated circuit (SIMMWIC) technology. Monolithically integrated coplanar Schottky barrier diodes are used as rectifying elements embedded in different antenna structures. Both p- and n-type Schottky barrier diodes are realized with cutoff frequencies up to 1 THz. The rectennas are combined with a CMOS preamplifier mounted as a multichip module (MCM) next to the rectenna on a high-resistivity silicon substrate. An amplification of 32 dB is measured. Maximum sensitivity of the detector circuit including preamplification is 1600 mV/mW/spl middot/cm/sup -2/ at 94.6 GHz. For a monolithic integration of high-frequency circuits with low-frequency control and signal-processing electronics, the monolithic integration of CMOS circuitry on high-resistivity silicon is discussed.

SIMMWIC rectennas on high-resistivity silicon and CMOS compatibility

An integrated transmitter at 80 GHz is presented. This device finds many applications in civil sensor and communication systems, and is employed in automotive applications. The device consists of an IMPATT diode and a slotted patch resonator. The resonator acts simultaneously as an antenna. The resonator impedance seen by the IMPATT diode is calculated by means of a full wave analysis and the matching of the IMPATT diode is investigated using a large signal analysis. The transmitter devices have been fabricated employing a SIMMWIC (silicon millimeter wave integrated circuit) fabrication process and deliver a radiated power of up to 1 mW at 79 GHz. An excellent carrier-to-noise ratio of 81.7 dBc/Hz at an offset of 100 kHz has been achieved. The deviation of the measured values from the theoretically predicted values of frequency and power is -5.9% and -1.5 dB, respectively. >

A monolithic integrated millimeter wave transmitter for automotive applications

An integrated active antenna with a polarization purity better than 28 dB and a radiated power of 8 dBm at 75.7 GHz is presented. The linearly polarized radiator consists of a planar resonant antenna and a transit-time diode monolithically integrated on a silicon substrate. This active antenna finds various applications in low-cost multi-channel sensor systems, e.g. for object classification. Guidelines for the design are discussed. The characterization of the fabricated SIMMWIC devices includes measurements of output power, polarization purity, and far-field pattern. Moreover, the oscillation frequency of the devices has been successfully stabilized using subharmonic injection locking. The FM noise behavior of the locked oscillator has been characterized. The measured results are presented and compared to theoretical calculations.

https://ieeexplore.ieee.org/iel3/3773/11021/00511217.pdf

A SIMMWIC 76 GHz front-end with high polarization purity

In this paper a method is presented to examine the suitability of planar structures to work as a resonator for IMPATT diodes in a frequency range above 70 GHz. The IMPATT diode is replaced by a Schottky diode previously characterized by impedance. It is suggested to test the suitability of the resonator for an IMPATT diode by employing the radiation characteristics of the structure. This set-up allows the determination of the detector's sensitivity depending on the frequency. The sensitivity corresponds to the matching of the resonator and the Schottky diode. Thus, for maximum sensitivity the equation Z/sub Schottky//spl ap/-Z*/sub IMPATT/ allows to assess the suitability of the planar structure to function as a resonator for an IMPATT diode. >

Characterization of planar resonators by means of integrated Schottky diodes

A planar radiating oscillator, consisting of a planar resonant antenna and WATT diode monolithically integrated on a silicon substrate, is presented. By exploiting the resonant characteristics of the planar antenna and directly locating the active element in the planar structure, a self-radiating oscillator was achieved. By using this configuration space requirements and parasitic losses of the presented transmitter are reduced to a minimum. Because of reduced size and easy manufacturing, this kind of monolithic integrated transmitter is excellent for low-cost sensor systems in automotive applications. This oscillator should find various applications in low-cost sensors, e.g., velocity sensors. The design tools are discussed and the calculated results are compared to measurements.

A radiating monolithic integrated planar oscillator at 55 GHz

SIMMWIC’s (Silicon Monolithic Millimeter Wave Integrated Circuit) have gained increasing interest as receivers and transmitters in the millimeter wave region. They provide new solutions for near-range sensor and communication applications in the frequency range above 50 GHz. Particular advantages are the capability of very easy monolithic integration of a complete radiating oscillator, a high degree of technological reproducibility, small size and, thus, low cost1. A typical millimeter wave front-end consists of an IMPATT diode integrated in a planar resonator. This resonator acts simultaneously as an antenna resulting in an active antenna configuration. Due to the low q-factor of the resonator, for some applications, like FM-CW-radar, the frequency stability and the phase noise behavior of the front-end are insufficient. Using a phase-locked-loop is a practicable way to stabilize the oscillation frequency and suppress the phase noise. However, many millimeter wave components such as frequency dividers, voltage controlled oscillators (VCO’s) and phase/frequency comparators are required resulting in an expensive and complex multichip system.

A. Stiller

Papers

A monolithic integrated millimeter wave transmitter for automotive applications

A SIMMWIC 76 GHz front-end with high polarization purity

Characterization of planar resonators by means of integrated Schottky diodes

A radiating monolithic integrated planar oscillator at 55 GHz

FM Noise and Synchronization Behavior of a SIMMWIC 76.5 GHz Front-End