I-Tseng Tang

A Compact Quad-Band PIFA by Tuning the Defected Ground Structure for Mobile Phones

The development of compact antennas plays an important role in the rapidly growing mobile communication market. This paper presents a novel design technique of the quad-band small internal antenna covering GSM-900/DCS-1800/PCS-1900/IMT-2000 bands. The innovative quad-band built-in handset antenna is developed within the limit of a 44×25×4mm3 volume. The following document describes a new idea of increasing operational bandwidth for the compact planar inverted F antenna (PIFA). The proposed compact antenna introduces the open-end slots in the ground plane almost all under the radiating patch. The size reduction method is attractive for practical antenna implementations. In addition, the end user’s hand handling effects on the performances of the proposed antenna are studied. Received 6 July 2010, Accepted 7 August 2010, Scheduled 13 August 2010 Corresponding author: I-T. Tang (tangitseng@gmail.com). 174 Lin, Tang, and Hong

Flower-Like CPW-FED Monopole Antenna for Quad-Band Operation of Mobile Handsets

A novel flower-like quad-band CPW-fed monopole antenna using a dual-inverted-L loop and four branched-inverted-L strips is proposed and investigated experimentally. The antenna that occupies area of 69 × 50 mm2 is demonstrated on a FR4 substrate including the ground plane. The proposed antenna is easy to be integrated with radio-frequency/microwave circuitry for low manufacturing cost. The proposed quad-band antenna has enough bandwidth to cover the GSM (880–960 MHz), DCS (1710–1880 MHz), PCS (1850–1990 MHz), and WLAN (2400–2483.5 MHz) bands for VSWR ≤ 2. The measured peak gains are 1.44, 3.55, 3.287, and 2.7 dBi, at the GSM, DCS, PCS, and WLAN bands, respectively. Good monopole-like radiation patterns and antenna gains have also been obtained.

A compact slot UWB antenna with CPW-fed

A simple and novel compact CPW-fed slot antenna which has small dimension of (25 times14 mm2) is proposed for Ultra-Wideband applications. The special is inner antenna which also has smaller dimension of (7 times 5 mm2). To miniaturize the antenna size, the accessional ground planes and staircase shape antenna are introduced. The proposed planar coplanar waveguide fed antenna is easy to be integrated with radio-frequency /microwave circuitry for low manufacturing cost. The optimal dimensions can be achieved by a parametric analysis. The designed antenna operates over 3.0 to 10.9 GHz for VSWRles2. The antenna also shows omnidirectional radiation patterns and that is suitable for UWB applications.

Spiral and Multimode Antenna Miniaturization for DTV Signal Receptions

In this letter, a novel broadband miniaturized antenna is presented. This antenna is proposed for operation in the digital television (DTV) reception band (470-862 MHz) throughout the world. This antenna uses a 50- microstrip line to feed. To achieve broadband characteristics, the proposed antenna is constructed using seven resonance paths in the ground plane. For compact structuring, a signal line is used in the proposed antenna, while ground plane coupling is used to induce the capacitance effect. The impedance matching and bandwidth of the proposed antenna are significantly affected by the sheet metal on the signal line. The antenna is able to realize an omnidirectional radiation pattern over the entire frequency band. Furthermore, the measurement results agree with the simulation ones.

INTERDIGITAL CAPACITOR IFA FOR MULTIBAND OPERATION IN THE MOBILE PHONE

A compact and simple interdigital capacitor inverted- F antenna (IFA) operated at its quarter-wavelength (‚=4) mode as the fundamental resonant mode for achieving multiband operation in the mobile phone is designed. The proposed antenna consists of a monopole antenna and an IFA. The proposed interdigital capacitor IFA has a simple structure of comprising two meandered radiating strips of length about ‚=4 and is fed using an interdigital capacitor coupling feed. The two meandered radiating strips also generate two ‚=4 resonance modes at about 900MHz and 2100MHz to cover the GSM850/900/1800/1900/DCS/PCS/UMTS bands and the 2.4GHz WLAN (IEEE 802.11b) band operations. Further, the proposed antenna has a simple planar structure and occupies only a small area of 10 £ 40mm 2 on the system circuit board of the mobile phone. This proposed antenna with multiband, broadband matched impedance, stable radiation patterns, constant antenna gains, good radiation e-ciency and compact size can be suitable for mobile phone applications.

SIMULTANEOUS SWITCHING NOISE MITIGATION CAPABILITY WITH LOW PARASITIC EFFECT USING APERIODIC HIGH-IMPEDANCE SURFACE STRUCTURE

A novel design with low parasitic effect for eliminating the simultaneous switching noise (SSN) in high-speed circuits is proposed by using the aperiodic high-impedance surface (A-HIS) structure. The A-HIS configuration is proposed in this work, revealing suppression of the SSN from 1.1∼ 1.85 GHz. It is shown that the HIS structure with aperiodic design, the SSN will be effectively suppressed. The undesired resonances of the proposed A-HIS structure are less than that of the conventional structure below 1 GHz. Less undesired peaks will ensure the electromagnetic interference (EMI) and signal integrity (SI). The measured results show very well compared with the conventional periodical HIS structures. The suppression results of the proposed A-HIS structure is checked by both measurement and simulation results. By using this proposed method, the simplicity of the structure is easier to fabricate as well as to route signal lines with a perfect power/ground planes. In addition, the proposed designs provide excellent SSN suppression and good signal integrity (SI) as the conventional structure.

A novel integrable surface acoustic wave notch filter

Abstract Although surface acoustic wave (SAW) notch filter was investigated in the past, the structures of these devices often needed the extra lumped-element such as resistance R , capacitance C , and inductance L so that the devices are complex and integrated hardly. From this, we offer a simple kind of the planar structure to the novel SAW notch filters that have smaller size and can be fabricated easily. We adopt the SAW and the interdigital transducer’s (IDT’s) theory to fabricate the SAW notch filter. In this paper, we use an IDT finger width 8 μm with conventional photolithography process, lift-off technique, and IDT electrode to fabricate on 128° rotated YX-cut lithium niobate (LiNbO 3 ). Finally, we get the frequency responses of the novel SAW notch filter with the center frequency 113.4 MHz, the 3 dB bandwidth 0.36%, and the insertion loss S 21 =−10.583 dB.

Compact Pentagon Ultra-Wideband Bandpass Filter with Good Out-of-Band Performance

A novel compact pentagon ultra-wideband band-pass filter with spurious suppression over a very wide band is proposed. The filter is based on a circuit model using hybrid bended pentagon microstrip and five quarter-wavelength short-circuited stubs, and using double reverse U-shaped defected ground structure (DRU-DGS) provides attenuation pole to suppress the second spurious harmonic. The design was successfully realized in theory and verified by full-wave EM simulation of the full layout and the experiment. The proposed filter had a good performance, including an ultra-wideband bandpass (3.1–10.6 GHz), low insertion loss, sharp rejection, and a flat group delay of about 0.10 ns over the most center band. The filter also demonstrated an UWB reject band from 12 GHz to more than 20 GHz at –20 dB.

Compact five-band meandered PIFA by using meandered slots structure

The development of small integrated antennas plays a significant role in the progress of rapidly expanding wireless communication applications. The proposed planar inverted-F antenna is designed for multi-bands operation by using three meandered slots etched in the meandered patch pattern. The novel meandered antenna is able to operate in the GSM-900/GPS-1575/DCS-1800/PCS-1900/WLAN bands with a voltage standing wave radio (VSWR) better than 2.5. Modifying the three meandered slots structure of antenna is alternative way to obtain the desired multi-bands resonance frequency operation and reduce 50% of the conventional meandered antenna size. The compact multi-bands method is attractive from the point of view of practical antenna performances.

Performance comparisons of PAPR reduction methods for the OFDM system

OFDM (Orthogonal Frequency Division Multiplexing) technique has been widely adopted in many wireless communication systems due to its high data-rate transmission ability and robustness to the multipath fading channel. One major drawback of the OFDM signal is the high peak-to-average power ratio (PAPR) problem. The high PAPR results in the in-band distortion and out-of-band radiation when the OFDM signal is fed into a nonlinear power amplifier (PA). In this paper, we propose a partition dummy sequence insertion (PDSI) method to reduce the PAPR problem and compare with the DSI method. Simulation results of the PAPR reduction and bit error rate (BER) performance for the proposed method are performed to demonstrate its capabilities.