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A fully integrated 2.4/5 GHz transceiver for IEEE 802.11a/b/g WLAN standards implemented in a 0.18um CMOS technology is presented. The IC employs fully integrated dual-conversion architecture without a SAW filter. The receiver chain achieves an overall 2.5dB and 3.5dB NF at 2.4/5 GHz respectively and provides over 100dB gain range. The transmitter delivers +5dBm output P1dB with an output power of...
This paper reviews the recent research results of monolithic millimeter-wave integrated circuits (MMICs) implemented in Si-based IC technologies at National Taiwan University. State-of-the-art results were achieved using standard MS/RF CMOS and SiGe BiCMOS processes. Both the MMIC designs and measured performances are described, together with the comparisons of recently reported results.
Multilayer perceptron neural network (MLPNN) model is established to determine the characteristic parameters of quadruple-ridged square waveguides. The model is trained with backward propagation (BP) algorithm. Results obtained by MLPNN model are in good agreement with those available data. A design example is then presented for the quadruple-ridged square waveguide operating at 18-40 GHz. The proposed...
In this paper, a single-ended downconversion sub-harmonic mixer is implemented using 0.35-mum SiGe BiCMOS technology. Two lumped- element rat-races are applied to generate differential LO and RF signals. This single-ended rat-race mixer has the conversion gain of 25 dB and high port-to-port isolations at 10 GHz. The input return loss is about -10 dB and the compact chip size is 0.8 mm x 0.9 mm. The...
A novel compact slot antenna fed by the conductor-backed coplanar waveguide (CBCPW) is proposed. The antenna is composed of a CBCPW-fed slot dipole and an additional arc-slot in front of the dipole. Compared to the CBCPW-fed slot dipole without the arc-slot, the antenna gain is improved significantly. The antenna occupies a small area and uses only one layer of dielectric substrate and a single feed...
A new single-feed method for circular polarized square-ring microstrip antenna is proposed. The circularly polarized antenna operates at its fundamental TM11 mode is fed by a J-shaped structure through proximity coupling. Simulation shows that the source current, which flows in the annular section of the J-shaped feed, induces a circulating current on the annular ring radiator flows in the opposite...
The complex permittivity of blood is changed by the change of glucose concentration in millimeter-waves. In this paper, a new technique is proposed to obtain blood glucose level using resonant applicator and measuring reflection coefficient. It is found that by measuring the reflection change using newly developed high sensitivity applicator, blood glucose level can be obtained in vivo.
The model and simulation of a novel substrate integrated waveguide (SIW) sum-difference comparator based on 3 dB-coupler with 90deg phase delay is proposed. Equivalent model method is used to determine initial geometric sizes and numerical software simulation is used to make optimization and obtain electrical characteristic variations and electromagnetic field distributions. An example comparator...
A low-loss LIGA-fabricated conductor- backed coplanar waveguide and filter are presented. The copper transmission lines are 517 mum thick and are fabricated directly on quartz in a uniplanar X- ray lithography process. The conductor-backed CPW achieves a measured attenuation of 0.090 dB/cm at 18 GHz with low dispersion over the bandwidth of interest. A bandpass filter is realized using the thick-metal...
A novel framework is proposed and demonstrated where satellite visibility viewed from running vehicle is economically and effectively evaluated with such low cost GPS receivers like equipped in automobiles. Our preliminary experiment articulated even economical L1 C/A 1.5 GHz GPS receivers can create enough precise database of ground feature blockage, if only two statistical parameters the author...
We have observed broadband VHF radio waves to investigate the propagation of distant TV broadcast waves. From the end of January to the middle of February, 2006, in the evening various radio waves at several frequency in 47.5-76.0 MHz have been often received with high intensity at Tateyama observatory(34deg59'N, 139deg54'E). Many of them are considered to come from China because their frequencies...
In this paper, a tri-band antenna for wireless communication applications is presented. The antenna is composed of two different elements, that are an inverted-L monopole operating at 5.2 and 5.8 GHz and a coupled modified half-wavelength open-loop resonator operating at both 2.4 GHz and 3.5 GHz to cover the required bandwidth for IEEE 802.11a/b/g WLAN and IEEE 802.16e. The proposed antenna has the...
In this paper, we propose a dual wide band chip internal antenna which can be applied to actual portable phones. The size of this antenna is 8times3.2times20(mm3). The minimization of this antenna was realized by using meander line structure and spiral line structure on FR-4 of dielectric permittivity epsivr= 4.4. We can get the wide-bandwidth in the upper band by overlapping high order resonances...
In this paper, we investigate the performance of two dual-band printed CPW-fed antennas, which have C-shaped and T-shaped geometrical shapes, for wireless body-worn applications. The simulated results in reflection coefficient, radiation characteristics and specific absorption rate (SAR) are presented.
An alternative derivative superposition (DS) approach is proposed to reduce nonlinear distortions in field effect transistors (FETs). Based on the conventional DS method, the described technique offers a compromise to intermodulation correction capability and circuit complexity. Intermodulation cancellation is achieved by synthesising a small-ripple transconductance derivative for a given range of...
The influence of phase noise and frequency sweep linearity on radar system performance is discussed using measurement data of a linear frequency modulated continuous wave (LFMCW) radar transmitter, consisting of a 77-GHz voltage controlled oscillator (VCO) and a 19-GHz down-converter manufactured in a 200-GHz silicon germanium (SiGe) technology.
Intermodulation distortion products and their asymmetry in microwave power amplifiers were drastically improved by intrinsic drain second-harmonic short-circuit termination. The FET drain parasitic inductance was taken into account to construct a series resonant circuit with a resonant-frequency at the second-harmonic. 1 GHz- band Si MOSFET power amplifiers were fabricated and the remarkable improvement...
This paper presents the microwave properties of barium strontium titanate (BST) thin films on r-plane sapphire substrates. A series of films with thickness 25-400 nm was prepared by pulsed laser deposition (PLD). Microwave properties of the films, including capacitance tunability and loss tangent, were extracted by patterning interdigitated capacitors (IDCs) on the film surface. The highest tunability...
This paper presents a new symmetric multilayer coupling configuration in order to reduce the size of microwave bandpass filter. To verify this approach, simulation and experimental investigation were made. A four sections bandpass filter was design and implemented. Both simulation and experimental performances of the filter are presented and with a good agreement. By using symmetric signal trace and...
We report the 94 GHz CPW branch-line bandpass filter for planar integrated millimeter- wave circuits. The basic idea is to use the branch-line coupler as a transversal filtering section by connecting the coupled ports to the open load stubs and taking the isolated port as the output node. The 94 GHz bandpass filter exhibits an insertion loss of 2.5 dB with an 11.7 % 3 dB relative bandwidth at a center...
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