Development of multilayer liquid crystal polymer based radio frequency front-end receiving module at W-band
Date
2016
Authors
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Journal ISSN
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Publisher
University of Delaware
Abstract
To extend the sensing of human vision, radio frequencies have found prolific wireless applications in everyday life, e.g., wireless communication, radar, and radiometry. To overcome the crowded microwave spectrum, millimeter wave (mmW) frequencies have gained tremendous interest in these systems within several spectral windows, i.e., 35 GHz, 77 GHz, 95 GHz, and 140 GHz, due to their low atmospheric propagation loss. Additionally, mmWs can provide gigabyte data transmission rates for wireless communication systems and high resolution for radar and radiometry systems. To date, most mmW wireless systems have been implemented at Ka-band, i.e., 35 GHz, where they can be directly extended from the traditional microwave systems. However, as the frequency increases to W-band, such as 77 GHz and 95 GHz, RF engineers encounter nontrivial challenges from various technical aspects.
In a general sense, the most critical part of wireless communication, radar, and radiometry systems is the receiver. Despite the different mechanisms and applications of these receivers, it should be noted that they have similar front-end components, i.e., antennas, pre-amplifiers, and filters. Assembling these components can achieve a front-end receiving module, which could potentially be utilized in most wireless systems.
To this end, I present my work on the development of a W-band front-end receiving module, consisting of a high-gain antenna, high-gain low noise amplifiers, bandpass filters, transmission lines, and their transitions for interconnection. To minimize the dielectric loss, liquid crystal polymer (LCP) is selected as the module substrate, which has a low loss tangent and low dielectric constant at W-band. To achieve high density, light weight, low profile, and low power consumption, the proposed module is designed on a multilayer circuit. The multilayer circuit is fabricated using the commercial state-of-the-art large-panel circuit print technologies, achieving low unit price and short manufacturing cycle. Multi-chip module packaging technologies have been developed to achieve a net gain of more than 50 dB for the proposed module, while maintaining linear phase and low electromagnetic interference. By using the state-of-the-art low noise amplifiers, the noise figure of the module can be minimized below 6 dB at W-band, which can satisfy most wireless receiving applications. The designed antenna, transitions between various transmission lines, low noise amplifies, and developed integration and packaging technologies achieve an ultra-wide bandwidth that covers most of the frequencies in the W-band, providing sufficient bandwidth for gigabyte data transmission rates in wireless communication systems. For narrow-band applications, i.e., radiometry and frequency division multiplexing, the designed filters and directional filters can be utilized to pick out the frequencies of interest. In conclusion, the proposed front-end receiving module may find many applications in various wireless systems at W-band, i.e., wireless communication, radar, and radiometry.