We experimentally demonstrate a comparatively low-loss negative-index metamaterial with the magnitude of the real part of the index comparable with the imaginary part. Over 40% transmission is achieved in the negative-index region by structural adjustment of the impedance matching between the metamaterial and the air–substrate claddings. This structure has the potential of achieving high transm...

This paper aims to analyze the effect of application of defected ground structure (DGS) on the resonating properties of microstrip patch antenna. In order to obtain the comparative results a small size DGS has been introduced in the ground plane exactly under the feeding strip of the patch antenna. The representative results obtained from the simulations have revealed that the proposed antenna ...

This paper presents an approach to the development of a deductive object-oriented database system, describing the key design decisions and their consequences for implementation. The approach is novel, in that it integrates an object-oriented database system manipulated using an imperative programming language (ROCK) with a logic language for expressing queries and methods (ROLL). The integratio...

In this letter, a simple monopole antenna with variable band-notched characteristic for ultra wide band (UWB) function is proposed. Two L-shaped quarter-waveguide resonators coupled to the ground plane with two shorting tracks at the sides of the antenna are used to generate stop-band performance around 5.5 GHz (WLAN). The proposed antenna is fabricated on the substrate FR4 (relative permittivi...

Impedance matching circuit between radio frequency (RF) generator and the plasma load, placed between them, determines the RF power transfer from RF generator to the plasma load. The impedance of plasma load depends on the plasma parameters through skin depth and plasma conductivity or resistivity. Therefore, for long pulse operation of inductively coupled plasmas, particularly for high power (...

We consider a finite population of agents who exchange information and are paired every period to play a game with tension between risk dominance and Pareto efficiency. Agents sample past plays and corresponding payoffs from their information neighborhood, and choose one of two possible actions using either best response or imitation. Information exchanges and possible matchings each constitute...

The communication performance between reader and transponder in radio frequency identification (RFID) in the ultra high frequency (UHF) range strongly depends on the matching between transponder chip and transponder antenna. To assure power optimization in the forward link the input impedance of the antenna must be the complex conjugate of the chip’s input impedance. In this contribution a meas...

Here we explore the radiation features of optical nanoantennas, analyzing the concepts of optical input impedance, optical radiation resistance, impedance matching, and loading of plasmonic nanodipoles. We discuss how the concept of antenna impedance may be applied to optical frequencies and how its quantity may be properly defined and evaluated. We exploit these concepts in the optimization of...

This paper presents lumped dual-frequency impedance transformers for frequency-dependent complex loads. According to different dual-frequency allocations of a complex load in Smith chart, three types of impedance matching networks are presented respectively. Several kinds of lumped circuit blocks are used as basic elements for constructing these transformers with design formula deduced. Various...

For realizing a single chip microwave front-end, we studied the new design theory of impedance matching circuits for a Si-CMOS low noise amplifier (LNA) or power amplifier (PA), which are composed of coplanar waveguide (CPW) meanderline resonators and impedance inverters. We also present the simulated performances of CMOS-LNA or PA connected with input and output matching circuits. Finally, we ...