No description available.

This thesis presents the design and implementation of 140 GHz to 170 GHz transceivers in SiGe HBT technologies and a 95 GHz receiver in 65 nm CMOS technology. Optimization and modeling of all passive components and transistor biasing at peak-fT and peak-fMAX current densities are employed to obtain higher frequency operation of circuit blocks compared to state of the art. These circuit blocks include static and dynamic frequency dividers, voltage-controlled oscillators, and tuned mm-wave amplifiers. Design procedures for a 100 GHz static divider, a 136 GHz dynamic divider, as well as low-power divider topologies are presented. A methodology for the design of quadrature voltage-controlled oscillators in CMOS and SiGe technologies is described, together with a technique for reduced-power LO-path design. Tuned 5-stage 140 GHz, 160 GHz, and 170 GHz amplifiers with more than 15 dB in SiGe HBT technology are reported. Using these circuit building blocks, a 95 GHz receiver in 65 nm CMOS technology with 12.5 dB gain, 7 dB noise figure, and 206mW. Also, several 165 GHz transceivers are implemented in SiGe HBT technology. The 165 GHz transceivers that include an oscillator, a divider, RX, LO, and TX amplifiers, and a mixer, were designed with and without on-chip antennas. They have -3 dB conversion gain, all achieved at RF, and -3.5 dBm output power. Following that, a 140 GHz fully-integrated transceiver and a 140 GHz transceiver array with on-chip patch antennas were designed in a 0.13micron SiGe BiCMOS technology, demonstrating the highest integration levels at this frequency in silicon to date. These transceivers feature 136-145 GHz voltage-controlled oscillators, 20 dB receive-amplifiers and mixers,transmit-amplifiers with amplitude-shift keying modulation, and variable-gain IF amplifiers. At 140 GHz the transceivers have up to 32 dB conversion gain and -8 dBm output power. Wireless data transmission at 4 Gb/s was demonstrated over 1.15m with off-chip horn antennas, and over 2 cm with the on chip antennas. With on-chip antennas, the transceiver could detect a Doppler shift of as little as 25 Hz. Both transceivers were also operational in frequency-modulated continuous-wave radar mode.

This thesis presents the design and implementation of 140 GHz to 170 GHz transceivers in SiGe HBT technologies and a 95 GHz receiver in 65 nm CMOS technology. Optimization and modeling of all passive components and transistor biasing at peak-fT and peak-fMAX current densities are employed to obtain higher frequency operation of circuit blocks compared to state of the art. These circuit blocks include static and dynamic frequency dividers, voltage-controlled oscillators, and tuned mm-wave amplifiers. Design procedures for a 100 GHz static divider, a 136 GHz dynamic divider, as well as low-power divider topologies are presented. A methodology for the design of quadrature voltage-controlled oscillators in CMOS and SiGe technologies is described, together with a technique for reduced-power LO-path design. Tuned 5-stage 140 GHz, 160 GHz, and 170 GHz amplifiers with more than 15 dB in SiGe HBT technology are reported. Using these circuit building blocks, a 95 GHz receiver in 65 nm CMOS technology with 12.5 dB gain, 7 dB noise figure, and 206mW. Also, several 165 GHz transceivers are implemented in SiGe HBT technology. The 165 GHz transceivers that include an oscillator, a divider, RX, LO, and TX amplifiers, and a mixer, were designed with and without on-chip antennas. They have -3 dB conversion gain, all achieved at RF, and -3.5 dBm output power. Following that, a 140 GHz fully-integrated transceiver and a 140 GHz transceiver array with on-chip patch antennas were designed in a 0.13micron SiGe BiCMOS technology, demonstrating the highest integration levels at this frequency in silicon to date. These transceivers feature 136-145 GHz voltage-controlled oscillators, 20 dB receive-amplifiers and mixers,transmit-amplifiers with amplitude-shift keying modulation, and variable-gain IF amplifiers. At 140 GHz the transceivers have up to 32 dB conversion gain and -8 dBm output power. Wireless data transmission at 4 Gb/s was demonstrated over 1.15m with off-chip horn antennas, and over 2 cm with the on chip antennas. With on-chip antennas, the transceiver could detect a Doppler shift of as little as 25 Hz. Both transceivers were also operational in frequency-modulated continuous-wave radar mode.

The demand for high data rate transfers in short range areas have been increasing significantly. Millimeter wave communication systems can fulfill the requirements for such applications due to the availability of wide bandwidths at these frequencies. Particularly, 60 GHz frequency band is more appropriate among other mm-wave bands because of the oxygen energy absorption resonance at this frequency. Millimeter wave antennas are one of the desired components in short range wireless communications. High gain and broadband antennas are required for this purpose. In this study, a fully planar 60 GHz antenna is introduced. Tapered dielectric rod antenna is chosen to achieve high radiation efficiency. The antenna is designed on two common substrates with high permittivity: alumina (Al2O3) and high resistive Silicon. Both substrates are very low loss and many designs for front-end components are developed on these substrates due to their high permittivity. In other words, the proposed antenna can be integrated with the front-end platform in the same substrate. In addition, the antenna feeding is the CPW line which makes it a convenient solution for integration of the antenna with RF front-ends such as MMICs or MEMS circuits in this range of frequency.

The demand for high data rate transfers in short range areas have been increasing significantly. Millimeter wave communication systems can fulfill the requirements for such applications due to the availability of wide bandwidths at these frequencies. Particularly, 60 GHz frequency band is more appropriate among other mm-wave bands because of the oxygen energy absorption resonance at this frequency. Millimeter wave antennas are one of the desired components in short range wireless communications. High gain and broadband antennas are required for this purpose. In this study, a fully planar 60 GHz antenna is introduced. Tapered dielectric rod antenna is chosen to achieve high radiation efficiency. The antenna is designed on two common substrates with high permittivity: alumina (Al2O3) and high resistive Silicon. Both substrates are very low loss and many designs for front-end components are developed on these substrates due to their high permittivity. In other words, the proposed antenna can be integrated with the front-end platform in the same substrate. In addition, the antenna feeding is the CPW line which makes it a convenient solution for integration of the antenna with RF front-ends such as MMICs or MEMS circuits in this range of frequency.

Recently, there is great interest in achieving higher-level integration, higher data rates, and reduced overall costs. At millimeter-wave (mm-wave) bands, the wavelength is small enough to realize an antenna-on-chip (AoC), which is an ideal solution for high compactness and lower costs. However, the main drawback of AoC is the low resistivity (10 Ω-cm) Si substrate used in the standard CMOS technology, which absorbs most radio-frequency (RF) power that was supposed to be radiated by the on-chip antenna. Moreover, due to the high relative permittivity (11.9) and relatively large electrical thickness of the Si, higher order surface wave modes get excited, which further degrade the antenna radiation performance. In order to alleviate the above-mentioned issues with the low gain of AoC, a combination of an artificial magnetic conductor (AMC) surface, a high dielectric constant superstrate, and a Fresnel lens is presented in this work. The AMC is realized in standard CMOS technology along with the AoC, whereas the superstrate and lens are part of a smart packaging solution. The AMC surface can change wave propagation characteristics at the operating frequency to achieve in-phase reflection, resulting in gain enhancement by reducing the loss in the substrate. The high dielectric constant superstrate behaves as an impedance transformer between the Si substrate and air, thus enhancing the coupling to air. Finally, the Fresnel lens enhances the gain by focusing the electromagnetic (EM) radiation beam at the boresight. For AoC realization, a standard 0.18 μm CMOS process was utilized. A coplanar waveguide (CPW) fed monopole on-chip antenna at 71 GHz, along with the corresponding driving circuit, was designed and fabricated. The AMC enhances the gain by 3 dB. Since the chip needs to be packaged anyways, in this work, we optimize the package to provide further gain enhancement. This smart package, comprising a superstrate and a Fresnel lens, provides a gain enhancement of 16 dB. The overall combination of the optimized AMC surface, superstrate layer, and lens package can provide a gain enhancement of around 19 dB. Furthermore, the package has been realized through additive manufacturing techniques that ensure lower costs for the overall system.

This dissertation proposes novel solutions for important drawbacks of antenna arrays. One of the main contributions of the presented work is size reduction and nulling performance improvement of traditionally large anti-jam global positioning system (GPS) arrays using miniature antennas and electrically small resonators emulating an engineered metamaterial. Specifically, a miniaturized coupled double loop (CDL) dual band antenna is first introduced as a small antenna element of the compact GPS array. The loops that are capacitively coupled using lumped element capacitor, and employ metallic pins around their perimeter to improve the radiation efficiency by achieving a volumetric current distribution. This design is employed for the implementation of a compact 2x2 GPS array by reducing the inter-element spacing between the adjacent elements. However, having the antenna elements in close proximity of each other yields to a high mutual coupling and potentially degrades the nulling performance. The mutual coupling is performed by observing the magnetic field distribution within the array. It is noticed that the mutual coupling can be reduced by using metamaterial resonators. The right hand circular polarization (RHCP) radiation nature of the array complicates the mutual coupling suppression as compared to linear arrays. It is determined that split ring resonator (SRRs) are effective to mitigate the mutual coupling problem if placed strategically around the antenna elements. The study is verified experimentally where the mutual coupling is reduced by more than 10 dB. Lowering the mutual coupling improved the array's nulling capability by increasing the nulls depth by 8 dB as well as enhancing the accuracy of the nulls' locations. The second major contribution of the presented work is to introduce a novel microfluidic based beam-scanning technique for the implementation of low cost mm-wave antenna arrays. Traditionally, beam scanning capability is obtained using mechanical steering of the entire antenna structure or electronic components such as switches or phase shifters. The former is bulky, whereas the latter technique requires integrating substantial and expensive hardware in the array's feed network. For instance, a beam-scanning 1x8 focal plane array (FPA) would employ 7 single pole double through (SPDT) switches in its feed network. If an 8x8 FPA is desired, then 8x7+8 switches are required that results in an efficient design in terms of power loss and cost. In this dissertation, the microfluidic principles are introduced for designing and implementing affordable beam scanning antenna array with high gain radiation. Specifically, a microfluidic-based focal plane array 1x8 (MFPA) is designed and implemented at 30 GHz. The proposed MFPA consists of microfluidic channels connecting reservoirs. Both of the channels and reservoirs are filled with a low loss dielectric solution, and the antenna is formed by using a small volume of liquid metal. The beam scanning capability is obtained by placing the array at the focal point of a microwave lens and moving the antenna among the reservoirs using a micropump. Therefore, the feed network is extremely simplified by avoiding using SPDT switches. In addition, a strategic design methodology for a completely passive resonant based corporate feed network is discussed. The array is characterized numerically and verified experimentally. The simulated and measured performances are in a very good agreement with ±300 FoV and > 21 dB realized gain. However, the array's radiation pattern exhibits high side lobe level (SLL) due to the resonant nature of the introduced corporate feed network. Consequently, new resonant and non-resonant straight based feed networks are introduced to alleviate the high SLL issue. Moreover, they are modeled with appropriate equivalent circuits in order to analyze the array's performance analytically in terms of -10 dB |S11| bandwidth and power loss. The analytical solution is based on the transmission line theory and two ports network analysis. It is verified with the full wave simulations and a very good agreement is observed. Using the straight feed network reduces the SLL to more than 20 dB relative the pattern's peak. This enhancement in the performance is verified experimentally as well by designing, fabricating and testing a 30 GHz MFPA fed using a resonant based straight network. A ±250 FoV is obtained with a SLL < -20 dB and 4% -10 dB |S11| bandwidth.

No description available.

High performance RF/mixed signal systems require new interconnect strategies to combine high frequency (microwave/mm-wave) circuitry with silicon mixed-signal and baseband digital processing. In such systems, heterogeneous vertical integration, in which circuits in different technologies can be stacked on top of each other within the system architecture, can reduce the overall system size and power consumption. Chip stacking also enables optimally-performing heterogeneous systems, because each level of the stack can consist of components fabricated in their most suited device or substrate technology. Two novel approaches for the vertical interconnection of heterogeneous integrated systems are proposed in this work. These approaches are related to flip-chip bonding techniques used in Radio-Frequency (RF)/microwave integrated circuits. The first proposed approach involves an interlocking mechanical structure that supports flip-chip assembled Monolithic Microwave Integrated Circuits (MMICs). Photolithographically patterned thick-film SU-8 structures are applied to both the chip and the carrier such that the chip self-aligns into place and mates with the carrier. Gold bumps embedded within the structures electrically connect the chip pads to the carrier pads. This method is demonstrated through the assembly of a SiGe power amplifier MMIC onto a high resistivity silicon carrier. The second proposed approach involves vertical interconnects consisting of room temperature liquid-state metals. The fluid nature of the liquid bumps allows them to be robust in the presence of thermo-mechanical stresses, such as Coefficient of Thermal Expansion (CTE) mismatch between the interconnected chips. SU-8 structures are used to form a shaping mold on the bottom carrier that contains the liquid metal. Gold posts are electroplated on the top chip, then mated with the SU-8 mold, thereby making contact with the liquid metal to form the electrical continuity. For each of these proposed methods, design and fabrication considerations are discussed in detail. RF measurements on prototype structures up to Ka band are performed to verify the functionality of the proposed methods. Given the results of these proof-of-concept efforts, electrical characteristics of the materials used in these methods are determined, and recommendations are provided for future improvements and refinements to these two techniques. / Master of Science

Yes / This paper presents a planar multi-circular loop antenna with a wide impedance bandwidth for next generation mm-wave systems. The proposed antenna comprises three circular rings with a partial ground plane with a square slot. The resonating structure is designed on a 0.254 mm thin RO5880 substrate with a relative permittivity of 2.3. The single element of the proposed design showed a resonance response from 26.5 to 41 GHz, with a peak gain of 4 dBi and radiation efficiency of 96%. The proposed multicircular ring antenna element is transformed into a four-element array system. The array size is kept at 18.25 × 12.5 × 0.254 mm3 with a peak gain of 11 dBi. The antenna array is fabricated and measured using the in-house facility. The simulated and measured results are well agreed upon and are found to be suitable for mm-wave communication systems.