Yuan-Chih Lin

Bio: Yuan-Chih Lin is an academic researcher from National Sun Yat-sen University. The author has contributed to research in topics: Antenna (radio) & Monopole antenna. The author has an hindex of 8, co-authored 11 publications receiving 281 citations. Previous affiliations of Yuan-Chih Lin include Industrial Technology Research Institute.

Thin internal GSM/DCS patch antenna for a portable mobile terminal

Abstract: A novel internal dual-band patch antenna with a small thickness of 3 mm for application in Global System for Mobile Communication/Digital Communication System (GSM/DCS) mobile terminals such as the mobile phone or Personal Digital Assistant (PDA) phone is presented. The patch antenna occupies an area of 15/spl times/60 mm/sup 2/, with its top patch embedded with a simple T-shaped slit, which separates the top patch into two resonant paths to generate two resonant modes for 900/1800 MHz operation. Then, by extending a small portion of the top patch beyond the top edge of the system ground plane of the mobile terminal, the antenna can provide two wide bandwidths covering the GSM/DCS bands. The proposed antenna is experimentally studied, and effects of the extended top-patch portion and the ground-plane length on the obtained bandwidths are discussed.

Internal Patch Antenna With a Thin Air-Layer Substrate for GSM/DCS Operation in a PDA Phone

Abstract: A thin dual-band internal patch antenna for Global System for Mobile Communication, 890-960 MHz/Digital Communication System, 1710-1880 MHz (GSM/DCS) operation in a Personal Digital Assistant (PDA) phone is presented. The antenna can generate two wide resonant modes for GSM (890-960 MHz) and DCS (1710-1880 MHz) operation, yet it requires an air-layer substrate of thickness 4 mm only, which is among the thinnest internal mobile phone antennas that have been reported. The antenna's top patch comprises a resonant narrow strip supporting a longer resonant path for GSM operation and a resonant subpatch supporting a shorter resonant path for DCS operation. By including a suitable widened end portion for the narrow strip and a suitable tapered end portion for the subpatch, increased bandwidths for the proposed thin internal mobile phone antenna are obtained. Detailed design considerations of the proposed antenna are described. In addition, the user's hand effects on the performances of the proposed antenna are studied

Internal shorted monopole antenna for the watch‐type wireless communication device for Bluetooth operation

Abstract: An internal shorted monopole antenna suitable to be embedded within the watch-type wireless communication device is presented. The antenna generally has a planar configuration and is mounted conformal along the side surfaces of the wireless device to operate as an internal or concealed antenna. The antenna also shows a low profile of 4 mm only, yet providing a wide bandwidth for Bluetooth operation in the 2.4 GHz band (2400–2484 MHz). In addition, the antenna is designed to be short-circuited to an upper ground plane mounted above the main system ground plane of the wireless device. With the proposed arrangement, reduced coupling between the antenna and the nearby lossy medium can be achieved. Hence, when the wireless device with the proposed antenna is worn around the user's wrist or forearm, which functions as a lossy medium, the antenna's radiation efficiency can still reach about 50% over the operating band. Details of the proposed antenna and the promising watch-type wireless communication device are presented. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 942–946, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22322

Thin internal planar antenna for GSM/DCS/PCS/UMTS operation in a PDA phone

Abstract: A novel thin internal planar antenna for GSM/DCS/PCS/UMTS quad-band operation in a PDA (personal digital assistant) phone is presented. The proposed internal antenna has a small thickness of only 3 mm, yet it is capable of providing two wide operating bands at about 0.9 and 2 GHz so as to meet the bandwidth requirements of the GSM/DCS/PCS/UMTS systems. Details of the design considerations of the proposed antenna are described, and the experimental results of the constructed prototype are presented. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 47: 423–426, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21190

Printed PIFA EM Compatible With Nearby Conducting Elements

Abstract: A novel printed planar inverted-F antenna (PIFA) with two shielding strips to allow the antenna to be electromagnetic (EM) compatible with nearby conducting elements is presented. That is, the proposed printed PIFA can be placed in very proximity to nearby conducting elements with small or negligible effects on the antenna performances. This attractive feature is mainly because the antenna's possible EM fringing fields are suppressed by the two added shielding strips at the feed and end portions of the printed PIFA. Details of the proposed printed PIFA are described, and a design example for wireless local area network operation in the 2.4 GHz band is studied.

Experimental Validation of Performance Limits and Design Guidelines for Small Antennas

Abstract: The theoretical limit for small antenna performance that was derived decades ago by Wheeler and Chu governs design tradeoffs for size, bandwidth, and efficiency. Theoretical guidelines have also been derived for other details of small antenna design such as permittivity, aspect ratio, and even the nature of the internal structure of the antenna. In this paper, we extract and analyze experimental performance data from a large body of published designs to establish several facts that have not previously been demonstrated: (1) The theoretical performance limit for size, bandwidth, and efficiency are validated by all available experimental evidence. (2) Although derived for electrically small antennas, the same theoretical limit is also generally a good design rule for antennas that are not electrically small. (3) The theoretical predictions for the performance due to design factors such as permittivity, aspect ratio, and the internal structure of the antenna are also supported by the experimental evidence. The designs that have the highest performance are those that involve the lowest permittivity, have an aspect ratio close to unity, and for which the fields fill the minimum size enclosing sphere with the greatest uniformity. This work thus validates the established theoretical design guidelines.

Printed Monopole Slot Antenna for Internal Multiband Mobile Phone Antenna

Abstract: A new internal multiband mobile phone antenna formed by two printed monopole slots of different lengths cut at the edge of the system ground plane of the mobile phone is presented. The antenna can generate two wide bands centered at about 900 and 2100 MHz to cover the GSM850/GSM900/DCS/PCS/UMTS bands and the 2.4-GHz WLAN band. Further, the antenna has a simple planar structure and occupies a small area of only. It is also promising to bend the antenna into an L shape to reduce its volume occupied inside the mobile phone. Good radiation characteristics are obtained over the two wide operating bands.

Printed $\lambda/8$ -PIFA for Penta-Band WWAN Operation in the Mobile Phone

Abstract: A small-size printed planar inverted-F antenna (PIFA) operated at its one-eighth wavelength (lambda/8) mode as the fundamental resonant mode for achieving WWAN (wireless wide area network) operation in the mobile phone is presented. The proposed PIFA has a simple structure of comprising two radiating strips of length about lambda/8 at 900 MHz and is fed using a coupling feed. Compared to the traditional PIFA using a direct feed, the coupling feed greatly decreases the very large input impedance seen at the lambda/8 mode for the traditional PIFA and results in successful excitation of the lambda/8 mode for the proposed PIFA. Two lambda/8 modes are generated by the two radiating strips and occur at close frequencies at about 900 MHz to form a wide lower band to cover GSM850/900 operation. The two radiating strips also generate two higher-order modes or lambda/4 modes at about 1900 MHz to form a wide upper band for GSM1800/1900/UMTS operation. Penta-band WWAN operation is hence achieved, yet the proposed PIFA only occupies a small printed area of 15times31 mm2 or 465 mm2 on the system circuit board of the mobile phone, which is about the smallest for the internal uniplanar printed antenna capable of penta-band operation that have been reported. Details of the proposed PIFA are presented. The specific absorption rate (SAR) and hearing aid compatibility (HAC) results for the proposed PIFA are also analyzed.

Quarter-Wavelength Printed Loop Antenna With an Internal Printed Matching Circuit for GSM/ DCS/PCS/UMTS Operation in the Mobile Phone

Abstract: A small-size printed loop antenna with an internal printed matching circuit capable of GSM/DCS/PCS/UMTS operation in the mobile phone is proposed. The antenna comprises an 85-mm long folded loop strip and an internal printed matching circuit encircled therein and formed by a coupling strip and an inductive strip. The loop strip is excited by the coupling strip to generate a 0.25 lambda resonant mode at about 900 MHz for GSM operation. For the inductive strip, it effectively causes a wideband higher order mode at about 1900 MHz for DCS/PCS/UMTS operation. Further, the antenna shows a uniplanar structure and requires a very small printed area of 170 mm2 on the system circuit board of the mobile phone, making it easy to fabricate at low cost. Details of the proposed antenna and its radiation performances including the SAR (specific absorption rate) results are studied.

Effects of Hand Phantom on Mobile Phone Antenna Performance

Abstract: With the continuous trend to smaller mobile devices with more functionality and more wireless bands, the possible insufficient over-the-air (OTA) becomes a growing concern for service providers. In addition to reduced radiation efficiency by smaller antennas in smaller phones, the head and in particular the hand may further impair radiation performance. The aim of this paper is to investigate the influence of the various parameters of the hand upon the OTA performance criteria to support the standardization process of the hand phantom and to provide the tools for optimization of handheld transmitters. The results reveal the following order of significance for small variations in hand parameters: 1) position of index finger; 2) distance between phone case and palm; 3) position of the other fingers; 4) size of the hand; 5) dielectric parameters; 6) wrist length and tilt. Some configurations may lead to a slight increase of the peak spatial SAR in the head. OTA assessment without the hand does not provide a good measure of phone performance in real life. However, good reproducibility of evaluations requires a precise definition of the hand, in particular its geometry and the phone position within the hand.