A new flexible and miniaturized power divider (PD), based on the Wilkinson PD topology, is carried out in this paper. Flexibility and size reduction are achieved simultaneously thanks to both an open-stub loading the input port and additional transmission lines (TLines) connecting the output ports to the isolation resistance. Design equations and rules are given. As a proof-of-concept, two PDs working at 2.45 GHz were fabricated and measured. Then, on the basis of the previous developments, a 1:4 power-dividing feeding network was realized. It highlights the high performance and flexibility of the proposed PD. Agreement between simulation and measurement results is very good, for PDs as well as for the feeding network, thus validating the proposed approach. This concept is straightforward to be applied at higher frequencies, in particular in the millimeter-wave range on CMOS technologies, where flexibility in the choice of the TLines characteristic impedances and size reduction are mandatory.

Design and fabrication of a traveling-wave printed planar composite right/left-handed (CRLH) antenna are presented in this paper. The proposed traveling-wave antenna constructed of four unit cells with b-shaped geometries, which each occupy 2.49 mm length, 6.32 mm width, and 0.8 mm height. In this paper, with designing the optimized b-shaped printed planar structure by the standard manufacturing techniques on the printed circuit boards, which perform the roles of the series left-handed (LH) capacitances (CL), the antenna size, bandwidth, and radiation specifications may be improved to the desirable range. Also, to obtaining the desired results the spiral inductors have been used, which play the roles of the shunt LH inductances (LL). The fabricated antenna with the proposed structure can be covered more from 2 GHz measured impedance bandwidth with minimum of the measured gain and radiation efficiency equal to 6.1 dBi and 52.3%, respectively, which happen at 9 GHz. According to the provided results, the proposed compact ultra-wideband traveling-wave antenna is a potential candidate to use in the embedded electronic systems and portable wireless communication devices.

Recent works have demonstrated the feasibility of microwave imaging using compressive techniques, exempting the use of active delay lines, phase shifters, or moving parts to achieve beamforming. With this method, waves are coded in a passive way by a compressive device to reduce the complexity of the transmitter and/or receiver chains of the telecommunication and radar systems requiring beamsteering. Such a technique is based on the exploitation of the frequency diversity, implying that a reduction of the compressive device's volume imposes a diminution of the number of driven antennas. In this paper, the improvement brought by simultaneous excitations of the compressive device is presented. Adapting a new mathematical formulation, it is shown that M inputs can send independent waveforms allowing the beamsteering of an N-elements antenna array, while maintaining N > M.

In this article, a new construction of a small planar dual-band fed printed monopole antenna based on coplanar waveguide is suggested. Impedance matching for dual-band operations is obtained by embedding three vertical strips with different sizes in the U-shaped conductor-backed plane. The main problem of the designed antenna is the measuring of the specifications with the Agilent 8722ES Vector Network Analyzer, when the coaxial cable is connected to the antenna. Hence, in this paper a new method for decoupling the cable from the antenna is presented. This method is based on using the ferrite bead. The ferrite bead reduces the cable radiation, so that its position plays the important part in the antenna radiation characteristics. The fabricated antenna includes the benefits of the miniaturized size and dual-band operating specifications, so that the mentioned properties have been achieved without modifying the coplanar-waveguide-ground surface or radiator patch. The antenna has the small size of 15 × 15 × 0.8 mm3and bandwidths with S11 < −10 dB about 2.2 GHz (5.05–7.25 GHz) for WLAN-band or IEEE 802.11a-band and 5.2GHz (7.6–12.8 GHz) for X-band, which correspond to 36 and 51% practical bandwidths, respectively. The antenna measured peak gains are about 1.8 dBi at WLAN-band and 4.3 dBi at X-band.

The narrow bandwidth of microstrip antennas is one of the most important features that restrict its wide usage. This paper presents a new coplanar waveguide-fed compact rectangular microstrip antenna with the improvement of the bandwidth using the slot geometry and cutting rectangular periodic edges for the patch radiator. To develop this structure, we have conducted many optimization and investigation using Momentum Software integrated into ADS “Advanced Design System” and comparison of the results with CST Microwave Studio. The comparison between the simulation and measurement results permits to validate the final achieved antenna with an improvement of the bandwidth. This antenna has wide matching input impedance ranging from 1.7 to 3.5 GHz with a return loss less than −10 dB, corresponding to bandwidth 69.7% at 2.6 GHz as a frequency center. The antenna achieved is a low cost, planar, and easy to be fabricated, thus promising for multiple applications in wireless communication systems. Details of the proposed antenna design and both simulated and experimental results are described and discussed.

A method allowing for reduction of coupling coefficients required for realization of two-section asymmetrical coupled-line directional couplers has been proposed. It has been shown that by connecting uncoupled left-handed and right-handed transmission lines between two coupled-line sections one can obtain greater design flexibility of the resulting circuit, simultaneously with the coupling reduction in coupled-line sections. Moreover, the proposed circuit features the properties of two-section asymmetric directional couplers offering wide operational bandwidth. The theoretical analysis has been verified by measurements of a 3 dB directional coupler operating at the center frequency f0 = 1.5 GHz having coupling imbalance δC = ±0.4 dB and bandwidth 0.75–2.3 GHz.

We present the realization of a cooperative radar system for ranging applications with integrated data-transmission capability. The simultaneous transmission is performed by the radar-hardware without the necessity of additional components or an auxiliary data-link. Therefore, the data are directly embedded in the transmitted chirp of a frequency-modulated continuous-wave radar sensor. A second station, acting as receiver, uses an identical, but unmodulated chirp for down-conversion. The resulting signal then is processed by a non-coherent demodulator setup, extracting the communication data. Measurement results from transmission of messages with different bit-rates are shown. By utilizing existing radar-hardware a transmission rate of up to 256 kbps is possible, without the need of a dedicated transceiver. Additionally, a method to optimize the ranging results by variable distribution of the available signal power between distance-measurement and communication system is presented.

In this article, the interesting constructions of the notch-loaded rectangular patch S-shaped antennas with L-strip feeding for multiband operations are presented. Implementing the L-strip feeding leads to creation of good benefits including several resonating frequencies, no cross-sectional area, simplicity in designing and constructing, stable gains and efficiencies, and the impedance matching. The proposed antennas are realized on the different substrate materials and the dramatic changes in characteristics are reported. These antennas are simulated, tooled, fabricated, and tested to provide the better performances in terms of return loss and bandwidth. Through the proper selection of the dimensions as well as the arrangement of the L-strip, the desired resonant modes of the antennas are excited in between 6–45, 3–20, and 2–16 GHz. Results of the radiation patterns, gains, and efficiencies of the constructed antenna on the foam substrate are studied and discussed. The maximum and minimum values of the gains and radiation efficiencies of this antenna are 10 dBi and 93%, and 1 dBi and 30%, respectively. The simulation results are obtained using method of moment based on the electromagnetic solver IE3D and are in good agreements with the experimental results, which were obtained from the spectrum analyzer.

In this paper a novel compact multi-band printed coplanar waveguide (CPW)-feed antenna for wireless local area network (WLAN)/WiMAX/RFID applications is proposed. The proposed antenna is composed of a multi-triangular structure as metal ground plane and the radiation element with four different branches, both of the structures are printed on the same side of a substrate and the antenna is fed by a CPW. By carefully tuning the locations and the sizes of these four branches, the antenna can yield three different resonating frequencies to cover the desired bands for WLAN/WiMAX/RFID applications. The simulated and measured results demonstrate that the proposed antenna has the impedance bandwidth (for return loss less than −10 dB) of 700 MHz (2.2−2.9 GHz), 540 MHz (3.16–3.7 GHz), and 850 MHz (5.05–5.9 GHz), respectively, which can cover the WLAN 2.4/5.8 GHz bands, the WiMAX 2.5/3.5 GHz bands, and the RFID 2.45/5.8 GHz bands.

The development in high-end microwave transceiver systems toward the software defined radio has brought about the need for tunable frontend filters. Although the problem is being tackled by the microwave community, there still appears to be an unmet demand for practical tunable filter technologies. With this motivation, this work presents a tuning method that delivers a resonator Q0 of 2000–3621 within a minimum tuning ratio of 1:1.42. A continuously tunable notch filter based on this tuning method is presented. The design is manufactured, measured, and verified. It is shown that the tuning technology compares favorably to other selected technologies.

In this paper a novel low pass filter (LPF) design procedure is proposed for electromagnetic bandgap based microstrip filters without using classical filter design approach. LPF is designed for ultra-wide stopband and sharp roll-off rate via proposed design procedure. It has been shown that finite periodic fan-shaped defected ground structures (FSDGSs) and double radial stubs (DRSs) yield broad stopband and very sharp transition band. The proposed LPF has −3 dB passband from dc to 1.49 GHz, and −20 dB broad stopband from 1.65 GHz up to 7.41 GHz. Full wave electromagnetic (EM) simulation of the proposed filter is achieved with ANSYS's High Frequency Structure Simulator (HFSS) and equivalent circuit (EC) model of the filter is proposed and verified via Applied Wave Research (AWR) software. To verify the simulations, filter is realized on ARLON AD1000 substrate, and measured with Agilent 5245A PNA-X Vector Network Analyzer. Measurement results of fabricated filter are in good agreement with EM and EC simulations.

This paper introduces a compact modified semi-circular monopole ultra-wideband (UWB) antenna. A compact antenna size (4.3 × 3.4 cm2) compared to the typical coplanar waveguide (CPW) circular monopole antenna (5.5 × 4 cm2) is achieved. The proposed antenna is completely proven for UWB communication performance. The antenna is matched over 8.4 GHz bandwidth (2.2–10.6 GHz), with reflection coefficient lower than −10 dB over the band. Matching bandwidth is verified through simulation and measurements of VSWR. Efficient power radiation over the band is proven through radiation efficiency. Radiation efficiency is not lower than 81% at the upper end of the band. Omnidirectional characteristics are proven through, firstly, measured transfer function magnitude at three different configurations, Face-to-Face, Face-to-Side, and Side-by-Side (all frequencies at different orientations), and, secondly, measured radiation pattern at three selected frequencies that span the bandwidth (all orientations at different frequencies). Moreover, the ability of the antenna to support, as narrow pulses as, 0.25 ns omnidirectionally is proven through detailed study for time response. Antenna transfer function is measured for magnitude and phase. Then, a first-order Raeighly pulse, that fulfils the FCC mask for emission restrictions, is applied at the terminals of a UWB system of the proposed UWB antenna. Finally, the output, barely distorted, normalized, pulse is compared to the input pulse.

A significant measureable development of inductance gain per unit of space in loop fractals for a suite of inductors which occupy the same layout space and require only a single-fabrication layer is investigated. All structures are fabricated on a borofloat glass substrate with dielectric constant loss tangent of 0.004. A chrome layer of 30 nm for adhesion followed by a 180 nm gold layer were sputtered and etched. To increase the surface area is implemented a simple geometrical strategy through fractalization and consequently the inductive performances is improved. Also, the higher fractal orders can be developed the inductive performance over 9 times from 0th to 3rd order. The fractal derivations of the original loop due to its space filling properties are examined and it suggests that although the effective electrode length increases, overall, the arrangement still essentially occupies the same space. In terms of design space for 0th, 3O-5O-7O of 1st, 2nd, and 3rd orders of fractals, 0, 26.2, 34.6, 38.6, 65.5, and 75.8% of occupied conductor surface area are saved. The measured inductances and resistances for aforementioned orders of fractals are 4.6 nH and 5 Ω, 8.6 nH and 10.5 Ω, 12 nH and 11.6 Ω, 12.8 nH and 17.3 Ω, 19.2 nH and 23.2 Ω, and 44.7 nH and 63.5 Ω, respectively.

This paper demonstrates an electromagnetic waves receiver (EMWR) with new architecture for finding the good performances at the very wide frequency range of 2.8 to 10.8 GHz. The proposed device applies conventional pulse position modulation (PPM) scheme for modulation. The combination of 8th–8th-order derivative of Gaussian pulse is used as impulse received signal. The EMW receiver circuit with core chip dimension of 32 × 10−3 mm2 was modeled in a 90 nm CMOS technology. The output amplitude pulse yielded 200 mV peak-to-peak under a supply voltage of 2.2 V. This circuit consumes 12 pJ/pulse at 0.5 GHz pulse-repeating frequency. The designed device can be employed in the transceiver systems in presence the multipath channel for 2.8 GHz to 10.8 GHz. Results express that the proposed system not only decrease the interference with narrowband (NB) systems, but is also robust against NB interference at the operating frequency of 7 GHz. Regarding to results, the EMWR can be used in radio frequency (RF) and wireless receiver applications.