Dual-frequency operation of CPW-fed antenna controlled by pindiodes

pin diode control is used to obtain a dual-band operation of a capacitively coupled patch antenna fed by a coplanar waveguide (CPW). The beam-lead pin diodes are inserted in the excitation slot and reduce the coupling length of the slot in their ON state. The frequency ratio of the two operating frequencies is 1.22 at 4.0 GHz. Details of the antenna design and experimental results are presented and discussed     

Efficient two-port antenna system for GSM=DCS=UMTS multimode mobile phones

The design of several two-port antenna systems for mobile phones is presented. All these structures are made up of two planar inverted-F antennas closely positioned on a small ground plane and radiating in the GSM900/DCS1800 and UMTS frequency bands. First, the antennas are simply associated at the top edge of the same printed circuit board. Thus, to improve their isolation and their total efficiency, a neutralisation effect is created by means of an optimised suspended line, which links the feeding strips of the radiators. The performance of these systems is measured and compared with theoretical results     

Design of an internal quad-band antenna for mobile phones

This letter presents the design of a compact Planar Inverted-F Antenna (PIFA) suitable for cellular telephone applications. The quarter-wavelength antenna combines the use of a slot, shorted parasitic patches and capacitive loads to achieve multiband operation. The commercial electromagnetic software IE3D is used to design and optimize the structure. The resulting antenna can operate from 880 to 960 MHz and 1710 to 2170 MHz covering GSM, DCS, PCS, and UMTS standards with a VSWR better than 2.5. Good agreement is found between simulated and measured results.     

Patch antenna with linear polarisation tilt control

The design of a linearly-polarised agile antenna is presented. The antenna is fed by a quasi-lumped coupler which has the ability to tune the magnitude ratio between its two outputs from -30-dB to 15-dB by modifying the bias of two varactor diodes. In this way the relative power fed to each orthogonal port of a patch antenna can be varied. Consequently, tilt control of the radiated linearly-polarised waves is achieved over a range of 90deg.     

Fabrication,simulations, and measurements of self-assembled millimeter-wave antennas for system-on-chip applications

A micro-electro-mechanical systems fabrication process has been developed to create self-assembled on-chip high efficiency antennas. The self-assembly creates out-of-plane antenna structures, which can have good radiation efficiency on low resistivity substrates. The structural material is SU-8 and the self-assembly curvatures are defined lithographically. The losses are reduced by having the antennas, transmission lines, and an isolating conducting ground plane placed on top of the supporting (and lossy) dielectric layer. The fabrication process includes deposition of a thick metal layer, which envelopes the antenna structure. This paper presents the fabrication process for a self-assembled monopole antenna, and numerical and physical experiments for the antenna pattern characteristics. The physical measurements show a realized gain (includes mismatch loss) of ?1.29 dBi at 59 GHz.     

Compact internal multiband antenna for mobile phone and WLAN standards

A novel internal planar inverted-F antenna (PIFA) suitable for handset terminals is presented. The structure combines shorted parasitic patches, capacitive loads and slots to achieve multiband operation. This compact antenna operates in the GSM, DCS, PCS, UMTS, HIPERLAN/2 and IEEE 802.11a bands within 2.5:1 voltage standing wave ratio (VSWR) and with good efficiency.     

Conception d’une antenne bibande à large bande pour la téléphonie mobile

The next mobile communication generation needs to be multi-band but also require a large bandwidth behaviour for each band, all this associated with dimensions as small as possible. The paper presents a radiating structure having these different properties. The realisation of this antenna is obtained using a folded planar metallic elements, ground wires and open quarter-wave slots. The influence of each technique and parameter is studied, analysed and optimised to obtain a single radiating dual-band / large bandwidth element, operating in GSM900, umts and also ism 2.4 communication standards. The radiation pattern of this antenna is suitable for mobile handset applications.     

Effect of reactive loading in microstrip leaky wave antennas

The influence of capacitors periodically soldered along the radiating edges of a leaky wave antenna (LWA) is described. As the propagation characteristics are modified, the main beam is tilted from the angle observed for the unloaded LWA. This property allows beam steering applications at a fixed frequency if bias-controlled reactances are used     

Dual-beam array of microstrip leaky-wave antennas

The authors present a small series-fed array of microstrip leaky wave antennas (LWAs) operating at 6.85 GHz and showing a narrow dual-beam pattern (17°×22°). The excitation is provided by a slotted coplanar waveguide. This type of antenna could be used as a radar sensor in Janus systems for contactless measurements of velocity and distance     

Dual-band HF-UHF RFID tag antenna

A dual-band HF and UHF RFID tag antenna with two feeding points is presented, fabricated and measured. A convenient HF resonance is obtained with an HF ASIC chip as well as good impedance matching with UHF ASIC chip in the European RFID UHF band. Tuning techniques of the design parameters are proposed, and tag performance in both frequency bands is evaluated.