Compact circularly polarised microstrip antenna design for dual-band applications

The design of a novel single-fed circularly polarised antenna dedicated for dual-band operations is presented. It is realised by integrating a dual-band dual-fed patch antenna with a dual-band branch-line coupler in a compact multi-layer structure. Measured impedance bandwidths of 20.1% (895 MHz) and 8.9% (2.397 GHz) are achieved.     

Compact broadband microstrip antenna

The development of a compact broadband microstrip antenna configuration is presented. The system uses a number of parasitic elements which are gas-coupled to a driven patch. The enhancement of bandwidth does not cause deterioration of the radiation pattern of the system.     

Compact two-port microstrip antenna

A compact two-port array antenna which operates in the X-band is described. This antenna, which combines a high gain with a relatively wide bandwidth, was conceived using mutual coupling and parasitic coupling techniques. The analysis and the simulations performed using the transmission line method and matrix algebra are briefly presented     

Compact triangular microstrip antenna

Loading a triangular microstrip antenna with a shorting pin can significantly reduce the antenna size at a given operating frequency. Experimental results of such a triangular microstrip antenna are presented. Variations of the resonant frequency of the triangular microstrip patch with different shorting-pin positions are given, and comparisons of the compact and conventional triangular microstrip antennas are also presented and discussed     

Microstrip antenna with integrated amplifier and phase shifter forDCS applications

A microwave microstrip probe fed antenna with an integrated voltage-controlled phase shifter and amplifier is demonstrated. It allows a phase shift of the feeding signal close to 100° in the entire DCS frequency band with a feeding signal gain of between 0 and 8 dB. Details of the antenna design, phase shift, matching and radiation patterns are presented     

Photonic RF phase shifter for harmonic downconversion in phasedarray antenna beam-forming applications

A photonic integrated-optic RF phase shifter for harmonic downconversion in phased array antenna beam-forming applications is presented. The subsystem consists of two integrated optic Mach-Zehnder interferometers fed with a combined signal from the receiving antenna and the local oscillator. This device achieves both phase shifting and harmonic downconversion of incoming RF signals     

Compact dualband rectangular microstrip patch antenna for 2.4/5.12-GHz wireless applications

A dual-band antenna is proposed for WLAN and WiMAX frequency bands. Two resonance frequencies are found to be 2.45 and 5.125 GHz and ?10 dB bandwidth of lower and upper resonance frequencies are 4.13 and 8.82 % respectively. It is observed that frequency ratio is more sensitive with the dimensions of L-shaped slot. The frequency ratio of the antenna for a given dimension of L-slot is found to be 2.092 and gain of the antenna is 3.9 dBi for lower resonance whereas 6 dBi at upper resonance. The theoretical results are compared with the reported experimental result as well as simulated results obtained from IE3D simulation software which are in close agreement.     

Compact microstrip antenna with dual-frequency operation

The characteristics of a single-feed dual-frequency compact microstrip antenna with a shorting pin are studied experimentally. Besides the compactness of the antenna, this dual-frequency design can provide a high frequency ratio of >3.0 between the two operating frequencies. Typical experimental results of the proposed antenna are presented and discussed     

Compact dual-band dual-polarisation microstrip patch antenna

A novel compact, conformal, dual-band, dual-polarisation antenna is presented. This antenna is capable of generating two distinct frequencies with different polarisation and radiation pattern characteristics: a monopolar mode for terrestrial cellular communication and a circularly polarised, upward oriented pattern for satellite mobile communication. Bandwidths of 2 and 4%, respectively, have been obtained in the two modes     

Miniaturised microstrip antenna for MMIC applications

A novel miniaturised quarter wavelength, H-shaped antenna which will find applications in monolithic microwave integrated circuit (MMIC) design is presented. The antenna occupies approximately one tenth of the substrate area of a half wavelength patch antenna. The effect on the resonance frequency, bandwidth and gain of the antenna are reported     

Centimeter-wave microstrip phase shifter on a ferrite-dielectricsubstrate

The propagation characteristics and fields of a microstrip transmission line on a composite ferrite-dielectric substrate are studied with a focus on its phase-shifting behavior. Two different methods are used for theoretical analysis, namely, the least-squares boundary residual method, which offers high precision, and a variational method in the spectral domain which requires a low computing time. Quasi-TEM (transverse electromagnetic) propagation is assumed in both cases. The results obtained are compared to experimental data, and good agreement is observed. Besides its easy design, this phase shifter presents the advantage of having a good peak power handling capacity as well as a low production cost because of the ease with which it can be integrated in planar systems     

Compact digital phase shifter utilising negative phase velocity

A compact digital phase shifter is presented utilising negative phase velocity in metamaterial technology. The phase shifter was designed and it was measured ranging from 0deg to 360deg with discrete increments of 60deg. The measurement result shows that the average increment of phase shift was X = 59.28deg and its standard deviation was sigma = 6.64deg.     

Compact dielectric loaded circularly polarised microstrip antenna

An investigation into the novel dielectric loading technique for reducing the size of low profile microstrip antennas is presented. Inserting or loading discrete dielectrics into the air substrate of a microstrip patch antenna can considerably reduce the antenna size while at the same time achieve good bandwidth and excellent axial ratio performance. Experimental and simulated results at L-band frequencies demonstrate the effectiveness of this approach     

应用于相控阵天线系统的C波段6位移相器设计

A C-band 6-bit digital phase shifter is presented.The phase shifter is based on the synthetic design of a high-pass/low-pass network and the all-pass network.The series scatter restrain method is also discussed.The phase shifter is fabricated in 0.25μm GaAs PHEMT technology and developed for C-band phased arrays,and the relative phase shift varies from 0 to 360 in step of 5.625°.The phase shifter,with a chip size of 4×1.95 mm~2,has achieved an insertion loss better than 6.4 dB,RMS phase error of less than 1.73°,and an input and output VSWR less than 1.6 at all conditions.     

Compact microstrip dual-band antenna for operation at 900 MHz

The design of a microstrip antenna that operates in two bands near 900 MHz from a single feed is described. The antenna exhibits good bandwidth characteristics while maintaining a compact form. Simulated and measured results of the performance of the antenna are presented.     

Compact uniplanar antenna for WLAN applications

A compact dual-band uniplanar antenna for operation in the 2.4/5.2/5.8 GHz WLAN/HIPERLAN2 communication bands is presented. The dual-band antenna is obtained by modifying one of the lateral strips of a slot line, thereby producing two different current paths. The antenna occupies a very small area of 14.5times16.6 mm² including the ground plane on a substrate having dielectric constant 4.4 and thickness 1.6 mm at 2.2 GHz. The antenna resonates with two bands from 2.2 to 2.52 GHz and from 5 to 10 GHz with good matching, good radiation characteristics and moderate gain     

Reduced-size microstrip patch antenna for Bluetooth applications

A novel reduced-size microstrip rectangular patch antenna for Bluetooth operation is presented. The proposed antenna operates in the 2400-2484 MHz ISM band. Although an air substrate is introduced, the antenna occupies a small volume of 33.3/spl times/6.6/spl times/0.8 mm. The gain and the impedance bandwidth of the antenna are predicted using a commercial finite-element method software package. The predicted results show good agreement with measured data.     

Compact circularly polarised microstrip antenna with bent slots

By embedding a group of four bent slots in a corner-truncated square microstrip patch, a single-feed compact circularly polarised microstrip antenna can easily be obtained. Results show that for a given circular polarisation (CP) operation, the proposed antenna can have an antenna size reduction of more than 50% as compared to the conventional CP design using a corner-truncated square patch without the slots. Moreover, the 50Ω feed position and truncated-corner size for achieving CP operation are found to be nearly independent of the bent slots introduced in the patch, which makes the proposed antenna easy to implement     

Compact design of single-feed circularly polarised microstrip antenna

A compact design of a single-feed circularly polarised (CP) microstrip antenna with relaxed manufacturing tolerances is presented. The CP operation of the microstrip antenna is achieved using a cross slot embedded on the radiating patch. By cutting an additional cross slot on the ground plane, not only the CP operating frequency can be decreased but also the slot-length ratio of the cross slot on the radiating patch can be considerably increased. In addition, the performance of the proposed design, such as CP bandwidth and peak gain, have no significant reduction.     

Compact circularly polarised microstrip antenna with slotted groundplane

A novel compact circularly polarised microstrip antenna with a slotted ground plane is proposed. By embedding a group of four bent slots in the ground plane and truncating a pair of patch comers in the radiating square patch, the proposed antenna can perform circular polarisation (CP) operation with a reduced antenna size at a fixed operating frequency. In addition, enhanced CP bandwidth and antenna gain for the proposed design are observed. Details of the antenna design and experimental results are presented and discussed