Reactive matching is extended to wide bandwidths using the impedance property of LC-ladder filters. In this paper, we present a systematic method to design wideband low-noise amplifiers. An SiGe amplifier with on-chip matching network spanning 3-10 GHz delivers 21-dB peak gain, 2.5-dB noise figure, and -1-dBm input IP3 at 5 GHz, with a 10-mA bias current.

A 3-10-Ghz low-noise amplifier with wideband LC-ladder matching network

To prevent interference problems due to existing nearby communication systems within an ultrawideband (UWB) operating frequency, the significance of an efficient band-notched design is increased. Here, the band-notches are realized by adding independent controllable strips in terms of the notch frequency and the width of the band-notches to the fork shape of the UWB antenna. The size of the flat type band-notched UWB antenna is etched on 24 times 36 mm2 substrate. Two novel antennas are presented. One antenna is designed for single band-notch with a separated strip to cover the 5.15-5.825 GHz band. The second antenna is designed for dual band-notches using two separated strips to cover the 5.15-5.35 GHz band and 5.725-5.825 GHz band. The simulation and measurement show that the proposed antenna achieves a wide bandwidth from 3 to 12 GHz with the dual band-notches successfully.

UWB Antenna With Single or Dual Band-Notches for Lower WLAN Band and Upper WLAN Band

This paper presents transient characterization of ultrawideband (UWB) body-worn antennas and on-body radio propagation channels for body-centric wireless communications. A novel miniaturized CPW-fed tapered slot antenna is proposed and used for transient measurements of UWB radio channels for body area network (BAN) and personal area network (PAN) scenarios. Unlike conventional UWB CPW-fed antennas, the proposed antenna employs two diverging tapered slots to provide smooth and stable impedance matching. Fidelity analysis is applied to evaluate the time-domain behavior of body-worn antennas and it is found that average fidelity obtained is 88% and 86% for the conventional coplanar waveguide fed antenna and the tapered slot antenna, respectively. However, the tapered slot antenna shows a significant size reduction and hence is suited for body-centric wireless communications.

Transient Characteristics of Wearable Antennas and Radio Propagation Channels for Ultrawideband Body-Centric Wireless Communications

In this letter, a band-notched ultrawideband (UWB) antenna is presented and the notched-band characteristic is realized by a compact coplanar waveguide (CPW) resonant cell (CCRC). The antenna with a total size of 46 mm $,times,$30 mm operates in a band from 2.67 to over 12 GHz, and shows omnidirectional radiation patterns. Measurements indicate that the antenna presents a notched band from 5.10 to 5.94 GHz for $ VSWR ge 3:1$, which covers the wireless local area network (WLAN) band. The time-domain behaviors and the CCRC are discussed and the group delay is given experimentally. Also, parametric studies are performed numerically in the end.

A Band-Notched Ultrawideband Printed Monopole Antenna

The introduction of electromagnetic (EM) media with unique field manipulation properties, collectively labelled as metamaterials, has boosted the interest toward the design, the fabrication, and the testing of artificial materials whose features can be engineered according to the applicative requirements and user objectives. In this framework, the long-term promise of reconfigurable metamaterial theory (i.e., the possibility to change the EM response of a 2-D/3-D material arbitrarily and in real time) has given the designers an extremely wide number of new degrees of freedom for the synthesis of innovative adaptive systems. Moreover, successful experimental validations of reconfigurable metamaterials in the entire EM spectrum from microwaves to optical frequencies have further stimulated academic and industrial interests in developing devices with enhanced performances, efficiency, and robustness. Nevertheless, the exploitation of reconfigurable metamaterials in commercial devices is still an open problem with several challenges from both the theoretical and technological viewpoints. This paper is then aimed at reviewing the latest advances on reconfigurable metamaterial engineering from the methodological perspective also providing a comprehensive and balanced survey on latest concepts, current trends, and envisaged future developments on this active field of research.

Reconfigurable Electromagnetics Through Metamaterials—A Review

This letter presents an ultra wide-band (UWB) antenna with a printed monopole structure fed by a coplanar waveguide (CPW) line. The antenna is analyzed by using the finite-difference time-domain (FDTD) method and genetic algorithm (GA) to achieve an ultra wide bandwidth characteristic. The measured frequency response shows an impedance bandwidth of 7.25GHz or 104.7% over 3.3 to 10.55GHz for VSWR less than 2.

Design of an ultra wide-band printed monopole antenna using FDTD and genetic algorithm

A tunable internal antenna with an epsilon negative zeroth order resonator (ENG-ZOR) for digital video broadcasting-handheld service is proposed in this paper. The antenna consists of two helical radiators, an ENG ZOR with two inductors and a variable capacitor to adjust the resonant frequency. The resonant frequency of the designed antenna can be swept from 474-702 MHz by adjusting the capacitance of the variable capacitor by controlling the DC bias voltage. The proposed antenna has a very compact size of 40 mm times 5 mm times 5 mm.

A Tunable Internal Antenna With an Epsilon Negative Zeroth Order Resonator for DVB-H Service

A wideband monopole antenna with dual band-stop function for WLAN (2.4 GHz/5 GHz) is presented. By cutting away an arched slot from the radiation patch and inserting spur-lines into the ground, dual band-stop functions for 2.4 GHz and 5 GHz WLAN bands are obtained. The proposed antenna operates over 1.9–11 GHz for VSWR <2, while providing a band-stop function in the frequency bands of 2.2–2.5 GHz and 5.15–6.1 GHz. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1646–1649, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23570

Wideband monopole antenna with WLAN (2.4 GHz/5 GHz) dual band‐stop function

In this paper, a CPW-fed ultra-wideband antenna for wireless body area network is proposed. The proposed antenna has a stair-shaped structure printed on the top of a substrate with the dielectric constant of 4.4 and occupies a small volume of 36mm × 24 mm × 1 mm. The antenna has an impedance bandwidth of 8 GHz from 3 to 11 GHz. The variation of group delay between the two proposed antennas is less than 1.09 ns and the maximum gain variation is about 6.5 dB. The radiation pattern over the frequency band of interest is changed from near omni-directional to directional pattern when the antenna is placed on the body.

A stair-shaped CPW-fed printed UWB antenna for wireless body area network

We propose a two-element diversity-antenna array using epsilon negative zeroth order resonator (ENG-ZOR) at the long-term evolution (LTE) and Wibro (WiMax in Korea) bands for the multiple-input multiple-output (MIMO) application. Each element is designed by utilizing an ENG ZOR unit cell with size of 10 mm × 6 mm × 6 mm. The lower resonant frequency is fixed by the zeroth order resonance of the ENG ZOR and the higher is selected by the radiator utilizing the first order resonance of the ENG ZOR. An isolator is added between the two elements in order to enhance the isolation characteristic at higher band of the designed MIMO antenna. The MIMO antenna is fabricated on the top side of the ground plane with size of 48 mm × 108 mm × 0.4 mm. The fabricated antenna has the isolation of about 20 dB at the lower band and higher than 13 dB at the higher band.

Jeongpyo Kim

Papers

Design of an ultra wide-band printed monopole antenna using FDTD and genetic algorithm

A Tunable Internal Antenna With an Epsilon Negative Zeroth Order Resonator for DVB-H Service

Wideband monopole antenna with WLAN (2.4 GHz/5 GHz) dual band‐stop function

A stair-shaped CPW-fed printed UWB antenna for wireless body area network

Dual band MIMO antenna using ENG zeroth order resonator for 4G system