Wireless biosensor applications require RF electronics to operate in immediate proximity of the body. This work investigates the effect of human body on RF circuits by simulations and measurements. Design methodology and initial design... more
Wireless biosensor applications require RF electronics to operate in immediate proximity of the body. This work investigates the effect of human body on RF circuits by simulations and measurements. Design methodology and initial design guidelines for body-worn discrete RF electronics are presented. The test structures are manufactured using printed electronics technology well suited for thin, flexible body-worn wireless sensor applications. The results indicate that in direct contact the human body significantly affects the performance of an RF circuit and needs to be considered. The research is relevant for modeling-based design of flexible body-worn wireless sensors.
Dielectric lens antennas are attracting a renewed interest for millimetre-and sub-millimetre wave applications where they become compact, especially for configurations with integrated feeds usually referred as integrated lens antennas.... more
Dielectric lens antennas are attracting a renewed interest for millimetre-and sub-millimetre wave applications where they become compact, especially for configurations with integrated feeds usually referred as integrated lens antennas. Lenses are very flexible and simple to design and fabricate, being a reliable alternative at these frequencies to reflector antennas. Lens target output can range from a simple collimated beam (increasing the feed directivity) to more complex multi-objective specifications. This chapter presents a review of different types of dielectric lens antennas and lens design methods. Representative lens antenna design examples are described in detail, with emphasis on homogeneous integrated lenses. A review of the different lens analysis methods is performed, followed by the discuss ion of relevant lens antenna implementation issues like feeding options, dielectric material characteristics, fabrication methods and a few dedicated measurement techniques. The chapter ends with a detailed presentation of some recent application examples involving dielectric lens antennas.
In this paper, on-body propagation modelling has been investigated applying various numerical computational techniques. Propagation measurements with body-worn antennas have been carried out at 2.4 GHz inside and outside an anechoic... more
In this paper, on-body propagation modelling has been investigated applying various numerical computational techniques. Propagation measurements with body-worn antennas have been carried out at 2.4 GHz inside and outside an anechoic chamber respectively for narrowband communication channel characterisation. Both simulation and measurement results have been also obtained at the UWB (ultra wide-band) band.
Application of a quasi-optical apparatus in the determination of the constituent parameters of materials is presented in this paper. Correction terms are introduced to remove the errors due to the misplacement of the sample and the... more
Application of a quasi-optical apparatus in the determination of the constituent parameters of materials is presented in this paper. Correction terms are introduced to remove the errors due to the misplacement of the sample and the calibration procedure. Good agreement was observed between manufacturer specifications and measurements after application of the correction terms.
This paper presents a compact system-on-package-based front-end solution for 60-GHz-band wireless communication/sensor applications that consists of fully integrated three-dimensional (3-D) cavity filters/duplexers and antenna. The... more
This paper presents a compact system-on-package-based front-end solution for 60-GHz-band wireless communication/sensor applications that consists of fully integrated three-dimensional (3-D) cavity filters/duplexers and antenna. The presented concept is applied to the design, fabrication, and testing of V-band (receiver (Rx): 59-61.5 GHz, transmitter (Tx): 61.5-64 GHz) transceiver front-end module using multilayer low-temperature co-fired ceramic technology. Vertically stacked 3-D low-loss cavity bandpass
The explosion-like spread of mobile telecommunication raises the problem of the exposure of the user to the electromagnetic field. The most realistic experimental investigations of the exposure can be made in phantoms. An E-Field probe... more
The explosion-like spread of mobile telecommunication raises the problem of the exposure of the user to the electromagnetic field. The most realistic experimental investigations of the exposure can be made in phantoms. An E-Field probe has been developed for this purpose. The isotropic probe consists of three mutually perpendicular short dipole antennas with zero-bias diodes in the gap and highly resistive wires to the preamplifier. The device can be applied in liquid phantoms. The technical details and first measurements are given
A reduced size antipodal Vivaldi antenna (AVA) design for the frequency band 6-18 GHz applications is presented in this paper. The proposed antenna shape is modified with the slot-loaded and circulated tips to achieve the high gain, good... more
A reduced size antipodal Vivaldi antenna (AVA) design for the frequency band 6-18 GHz applications is presented in this paper. The proposed antenna shape is modified with the slot-loaded and circulated tips to achieve the high gain, good VSWR and Radiation Pattern while the total size is reduced 66% compared with the reference antennas. Simulation and implementation results of the designed antenna are verified.
A new concept of a really compact corrugated horn antenna for global coverage with very low sidelobe and cross-polar level and quite wide bandwidth is presented in this letter. This consists on the concatenation of a choke antenna... more
A new concept of a really compact corrugated horn antenna for global coverage with very low sidelobe and cross-polar level and quite wide bandwidth is presented in this letter. This consists on the concatenation of a choke antenna together with a Gaussian profile horn antenna. A comparison of the performances of this horn design versus other author designs is included.
Measurement applications in a Compact Antenna Test Range (CATR) often require low cross-polarization or high polarization purity of the Quiet Zone (QZ). This requirement is often the main motivation for choosing the more complex and thus... more
Measurement applications in a Compact Antenna Test Range (CATR) often require low cross-polarization or high polarization purity of the Quiet Zone (QZ). This requirement is often the main motivation for choosing the more complex and thus expensive compensated dual reflector system as opposed to the simpler and cheaper single reflector system. In this paper, a novel, wide-bandwidth, conjugate matched feeding concept is presented. The concept aims at the cancellation of the geometrical optics cross-polar component in the QZ of standard single reflector CATR. The concept is valid for both side and diagonal fed configurations in dual simultaneous polarizations. The conjugate matched feeding concept, is described in detail and the cross-polarization cancellation properties of the proposed wide-bandwidth feed system is discussed. The concept is initially verified and the solution consolidated using numerical simulation of the reflector and full wave simulation of the feed system. The achievable wide-band cross-polar discrimination of 40dB in the QZ is confirmed on an operational bandwidth of 1:1.5. The conjugate matched feeding concept is then validated by a reduced hardware demonstrator and measurements. The target cross-polar discrimination of 40dB is confirmed by QZ probing of a standard single reflector CATR system.
In this paper, we present two thin/flexible printed monopole antennas for Wireless Local Area Network (WLAN) applications. The first design is a single band antenna which operates at 2.4 GHz while the second one is a dual band antenna... more
In this paper, we present two thin/flexible printed monopole antennas for Wireless Local Area Network (WLAN) applications. The first design is a single band antenna which operates at 2.4 GHz while the second one is a dual band antenna operates at 2.5 GHz and 5.2 GHz. The dimensions of the proposed antennas are: (26.5 mm × 25) and (35 mm × 25) mm for the single band and dual band respectively. Antenna properties, such as gain, far-field radiation patterns, coupling coefficient, expressed in terms of the scattering parameter S11 are provided. Design and simulations are performed using CST Microwave Studio software which is based on the Finite Integration Technique (FIT). Moreover, the effect of folding the antenna was performed experimentally on both designs to study its influence on the antenna performance. The achieved gain for the single band antenna is 1.8 dB with a measured bandwidth of 270 MHz. The dual band antenna achieved a gain of 1.8 dB and 4 dB at 2.5 GHz and 5.2 GHz respectively, and measured bandwidths of 305 MHz and 480 MHz at the first and second band respectively. The proposed thin and flexible designs along with antennas characteristics are suitable for integration into flexible technologies for WLAN applications.
