Towards an optimal trade-off of functional requirements against size, power and cost for phased array asics

Abstract – In this paper, we investigate various technologies and trade-offs used for manufacturing of integrated circuits with respect to their performance characteristics such as RF frequency, gain, noise figure, linearity and power consumption. This investigation is crucial for design of transceivers at microwave and higher frequencies. In the following, we show the in-house designed prototype of a highly integrated X- and Ku-band planar phased array receiver, having 8 channels and 64 antenna elements based on this investigation. The die size of the 8-channel phased array receiver with 2 GHz IF-bandwidth is 4 mm × 3.8 mm and the size of the prototype is 11 cm × 9.5 c

Miniaturized Phase-Shifters for Ka-Band Phased Array Antennas

Realizing robust and stable two-way links between the mobile users and the satellite is an extremely challenging RF/Microwave engineering problem. Low cost and low profile phased array is considered as the best solution for this problem. High performance low cost and miniaturized variable phase shifter is a key enabling technology for such complex smart phased array antenna system. This thesis aims at the investigation of the existing solutions to realize miniaturized, low-cost and at the same time integrable phase shifters for commercial phased array antenna systems. Among few existing approaches, analog phase shifting devices based on voltage-tunable materials offers a promising solution. Liquid Crystal (LC) and Barium Strontium Titanate (BST) are the two voltage tunable materials, which, beside their own primary applications, have found their way into Microwave and mm-Wave tunable device technologies. In this study the utilization of LC and BST in analog phase shifters has been rigorously investigated, the advantages and drawbacks of each when applied in different realizations have been discussed and further development and improvements in designs have been suggested. To achieve more compact designs for Ka-band phase shifters, a comprehensive design methodology for tunable filter-type phase shifter is proposed in this dissertation. The most commonly used phase shifting architectures for the phased array antennas are RF, LO, IF and base-band phase shifting. It should be mentioned that LO, IF and base-band phase shifting are not suitable for phased arrays with large number of elements due to the formidable cost and complexity, particularly for Tx phased array systems which require one phase shifter per antenna element to meet the radiation mask. Therefore, this thesis is concentrated on RF (Microwave/mm-Wave) phase shifting, which is the most common for large phased array antenna systems. Since one of the most important requirement in the design of Ka-Band phase shifters for phased array systems is the high level of miniaturization, dictated by antenna element spacing constraint, the thesis also addresses the highly compact structure of such phase shifters. In particular, a novel phase shifting concept based on very high dielectric constant materials has been explored. It is shown that by using this new concept, a highly miniaturized variable phase shifter with more than 360 degrees phase tuning range is attainable.4 month

Novel Approaches to the Design of Phased Array Antennas.

This dissertation presents three new approaches to the design of phased array antennas in order to reduce their complexity. The first approach is based on extended resonance technique which, unlike conventional phased array designs, achieves power dividing and phase shifting tasks within a single circuit. A new extended resonance circuit is developed here that increases the maximum achievable scan angle by three times compared to the extended resonance phased array demonstrated previously. In order to expand the size of phased array, a new modular approach is used enabling a scalable design of extended resonance phased array for the first time. By applying heterodyne-mixing concept, a modular 24 GHz phased array has been demonstrated. The second approach presented in this dissertation is based on a bi-directional feeding method. A new phased array is designed based on this approach which demands less phase shift from phase shifters compared to any of common phased arrays. The new bi-directional phased array allows for beam steering using only a single control voltage. A general design procedure for a bidirectional N-element phased array feed network is presented for the first time which allows applying this approach to phased arrays with any number of antenna elements. Furthermore, a new, compact phase shifter is designed and utilized in the phased array. A 2.4 GHz bi-directional phased array has been designed and fabricated. Finally, the third approach described in the dissertation allows the phase progression across the antenna elements to be controlled by using a single phase shifter. Therefore, the number of phase shifters required in the phased array is substantially reduced compared to conventional phased array designs which require a separate phase shifter per each antenna element. A variable phase shift is achieved in this approach by vector summation of signals. The amplitude ratios of these vectors are adjusted to provide a linear phase progression. This approach is much simpler than the traditional Cartesian phase shifting scheme. A 2 GHz phased array designed based on this approach has been fabricated and tested.Ph.D.Electrical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/89713/1/danial_1.pd

Evaluating Techniques for Wireless Interconnected 3D Processor Arrays

In this thesis the viability of a wireless interconnect network for a highly parallel computer is investigated. The main theme of this thesis is to project the performance of a wireless network used to connect the processors in a parallel machine of such design. This thesis is going to investigate new design opportunities a wireless interconnect network can offer for parallel computing. A simulation environment is designed and implemented to carry out the tests. The results have shown that if the available radio spectrum is shared effectively between building blocks of the parallel machine, there are substantial chances to achieve high processor utilisation. The results show that some factors play a major role in the performance of such a machine. The size of the machine, the size of the problem and the communication and computation capabilities of each element of the machine are among those factors. The results show these factors set a limit on the number of nodes engaged in some classes of tasks. They have shown promising potential for further expansion and evolution of our idea to new architectural opportunities, which is discussed by the end of this thesis. To build a real machine of this type the architects would need to solve a number of challenging problems including heat dissipation, delivering electric power and Chip/board design; however, these issues are not part of this thesis and will be tackled in future