Jia-Chi Samuel Chieh

A Bidirectional Microstrip X-Band Antenna Array on Liquid Crystal Polymer for Beamforming Applications

This communication presents for the first time a 16-element planar X-band bidirectional antenna array for beamforming applications. The planar (2D) antenna array is comprised of planar polygon slot antenna elements that utilize a metamaterial inspired reactive coupling element. Simulation and measurement results are presented for both a single antenna element and a 16-element planar array, which resides on a Liquid Crystal Polymer (LCP) substrate. Successful comparison between measured and simulated results verifies that the single antenna element achieves a 10 dB return loss bandwidth of 17.5% and the planar antenna array achieves a 10 dB return loss bandwidth of 25% both at a center frequency of approximately 11 GHz. The measured gain of the planar antenna array is more than 14.5 dBi with an efficiency of 65%. The overall size of the planar antenna array is 3.3λ° × 3.6λ° × 0.0093λ° at 11 GHz.

A light weight 8-element broadband phased array receiver on Liquid Crystal Polymer

In this paper we present a light weight broadband phased array hybrid receiver module on a multi-layer Liquid Crystal Polymer (LCP) substrate. The phased array module has 8 channels and is designed to operate in the Ka-band, from 32–37 GHz. A broadband linear tapered slot antenna array with a corporate power combiner, chip-on-board MMICs, and all control chips necessary for beam steering are all integrated on a multi-layered near-hermetic LCP substrate. The phased array antenna has a measured bandwidth of 5 GHz with ±30° beam steering capability from boresight, and shows less than 6.75° of beam squint across the full bandwidth of operation. The total size of the array is 100 mm × 100 mm with a board thickness of only 16 mils and weighs only 12.3 grams.

Development of a broadband Wilkinson power combiner on Liquid Crystal Polymer

We present the development of a broadband multi-section Wilkinson power combiner on Liquid Crystal Polymer (LCP) with integrated thin film resistors. The designed frequency of operation is from 2–18 GHz. The measured VSWR is better than 1.6∶1, the measured excess insertion loss is less than 1.1dB, and 11dB of isolation is measured across the full band. This work presents the highest performance Wilkinson combiner with the widest bandwidth ratio of 9∶1 reported in literature.

A wideband composite right/left hand rectenna for UHF energy harvesting applications

We present the design of a wideband composite right/left (CRLH) rectenna for energy harvesting. The frequencies of operation are in the lower UHF frequency band from 700 MHz to 1 GHz. In the UHF band, the wavelength is long and therefore energy harvesting schemes using traditional antennas are typically large. Utilizing the CRLH antenna adds an additional degree of freedom trading size with gain. The total size of the rectenna is 164 mm × 37 mm.

Millimeter-Wave Dual-Polarized High-Isolation Antennas and Arrays on Organic Substrates

We present the design and development of dual-polarized aperture coupled stacked patch antennas with substrate embedded air cavities. The antennas, targeted for operation in the W-band (75 - 110 GHz), are realized in a multilayer organic hybrid substrate utilizing both Kapton and liquid crystal polymer (LCP). Balanced and unbalanced feedlines are investigated in order to improve isolation and mitigate coupling between orthogonal polarized ports. Measured results for the single antenna element show good performance with a beamwidth of 90 ° and a 2.6:1 VSWR bandwidth of 23 GHz, and isolation of better than 17.8 dB. An eight-element linear array is also designed, fabricated and tested. The antenna array achieves a beamwidth of 13 ° with a 2.3:1 VSWR bandwidth of 7.2 GHz. Pattern measurements were achieved utilizing a millimeter-wave diode detector circuit implemented directly on the antenna substrate.

A bidirectional X-band antenna array on Liquid Crystal Polymer

A novel wideband planar polygon slot antenna with a metamaterial inspired reactive coupling element is presented. The antenna is printed on a Liquid Crystal Polymer (LCP) substrate and shows bidirectional radiation characteristics. The antenna, including the ground plane, occupies and area of 2.5 × 2.0 cm2. An impedance bandwidth of 17.5% is measured for the single antenna with a center frequency of 11.4 GHz. A 16-element antenna array utilizing this novel antenna is also presented. The simulated antenna array achieves a gain of 14.9 dBi with a radiation efficiency of 67% and an impedance bandwidth of 21%.

A W-Band 8 × 8 series fed patch array detector on Liquid Crystal Polymer

The design and fabrication of a W-Band 64 element antenna array detector based on the series fed patch antenna is presented. The prototype antenna array is fabricated on a Liquid Crystal Polymer (LCP) substrate using standard printed circuit board (PCB) manufacturing processes. Characterization of the unbalanced antenna is accomplished through the use of a millimeter-wave diode detector circuit, which is integrated onto the antenna array. Measurements show a beamwidth of approximately 13.2°. The total size of the antenna array with detector circuit is 4 cm × 3 cm.

A wideband and high gain V-band EBG patch antenna on liquid crystal polymer

In this paper, we present a novel and compact proximity fed V-band electromagnetic bandgap (EBG) patch antenna. The EBG structure serves to mitigate surface waves which can degrade the antennas performance. The proposed antenna is designed and fabricated on a multi-layer near hermetic Liquid Crystal Polymer (LCP) substrate. It is shown through simulation that up to 4.57 dB of gain enhancement is achieved through the use of an EBG structure to surround the patch antenna. The proposed antenna achieves a measured bandwidth of 10 GHz, which corresponds to a fractional bandwidth of 16.6%, and occupies a total area of only 7.4 × 5.6 cm2.

LCP for passive components

It has become increasingly apparent that LCP provides an ideal form, fit, and function for many broadband passive components. Since LCP is available in thicknesses less than 1 mil with low dielectric constant, this enables easy design of varying controlled impedances. Further, LCP’s property of being its own adhesive layer provides for a high layer count in a multilayer stack while simultaneously maintaining high-frequency performance that otherwise would be detuned by poor electrical ply layers. This chapter provides design and development examples of broadband passives that benefit from LCP. In section 6.1 we describe a broadband Marchand balun implemented on multilayer LCP covering 4–20 GHz and in section 6.2 a broadband Wilkinson power divider–combiner operating over 2–18 GHz. Section 6.3 presents a novel hybrid coupler using multilayer LCP to achieve a broadband design within a compact area. Broadband LCP Marchand balun A balun converts differential “balanced” signals into single-ended “unbalanced” signals, and vice versa. Marchand baluns are found in numerous microwave circuit designs owing to their characteristically wide bandwidth, low imbalance, and symmetric balanced ports. To achieve a wide bandwidth ratio, a Marchand balun is realized with multilayered broadside coupled microstrip lines implemented on LCP. A novel twin-thickness thin-film [1] structure has been devised specifically to reduce balun conduction loss without sacrificing operation bandwidth.