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Millimeter-wave coplanar stripline power dividers
We present the design, fabrication, and measurement of a 2-way modified Wilkinson divider constructed in a coplanar geometry exhibiting ultra wideband isolation, transmission, and port matching in the millimeter-wave frequency range. The proposed divider replaces the lumped resistor in the conventional Wilkinson divider with two quarter-wave length transmission lines, a phase inverter, and two 2Z
Single-layer fully-planar extended-composite right-/left-handed transmission lines based on substrate integrated waveguides for dual-band and quad-band applications
The implementation and application of single-layer fully-planar extended-composite right-/left-handed transmission lines (E-CRLH TLs) in substrate-integrated waveguide (SIW) technology are presented. The multiband CRLH behavior of these artificial lines is explained by considering the lumped element equivalent circuit model. The potential of these lines for dual-band and quad-band applications is
Numerical and experimental characterization of a button-shaped miniaturized UHF antenna on magneto-dielectric substrate
The design and characterization of a new broadband small patch antenna, based on an innovative magneto-dielectric material and suitable for wearable applications at 868 MHz, is presented. To reduce antenna dimensions, while preserving its radiation and matching performance, a barium-strontium hexaferrite BaSrFeO has been synthesized as the antenna substrate to achieve magnetic permeability double
Digital PA with voltage-mode topology using envelope delta-sigma modulation
This paper reports on digital transmitter architecture for the 450 MHz band using an envelope delta-sigma modulator realized in CMOS and a voltage-mode class-S (VMCS) power amplifier (PA) based on GaN monolithic microwave integrated circuits (MMICs). The class-S PA is characterized for narrowband single-tone signals and a single- as well as a four-carrier downlink wideband code division multiple a
Dielectric contrast measurements on biological substances with resonant microwave near-field sensors
Resonant substrate integrated near-field sensors are used for characterization of aqueous solutions at three different frequencies. In addition, Chinese hamster ovary (CHO) cells in a culture medium are characterized with the same sensors. Different concentrations as well as different vital states of cell suspensions are examined. The complex permittivity of the samples is evaluated using a linear
W-band active loads and switching front-end MMICs for radiometer calibration
A millimeter-wave monolithic integrated circuit consisting of a W-band (75?100 GHz) single-pole-five-throw (SP5T) switch and multiple internal active and passive loads for radiometer calibration was designed and manufactured in a low noise 50 nm GaAs metamorphic high electron mobility transistor technology. This highly compact and integrated front-end device for radiometer systems is capable of ul
Design, modeling and characterization of MMIC integrated cascode cell for compact Ku-band power amplifiers
This paper reports on the design of a new power cell dedicated to Ku-band power amplifier (PA) applications. This cell called ?integrated cascode? has been designed in order to propose a strong decrease in terms of circuit size for PA. The technology used relies on 0.25-?m GaAs pseudomorphic high electron mobility transistors (PHEMT) of United Monolithic Semiconductors (UMS) foundry. A distributed
Inkjet-printed paper-based substrate-integrated waveguide (SIW) components and antennas
This paper presents a novel technology for the implementation of substrate-integrated waveguide (SIW) structures, based on a paper substrate and realized by an inkjet-printing fabrication process. The use of paper permits to implement low-cost microwave structures and components, by adopting a completely eco-friendly implementation technology. SIW structures appear particularly suitable for implem
A proof of concept of a non-resonant near-field microwave microscope based on a high impedance reflectometer
In this paper, we present a non-resonant high impedance reflectometer with a reference impedance close to one of the tip probe of a near-field microwave microscope. We show that for an apex of the tip probe of 100 µm there is an optimum reference impedance close to 1 k?. To validate this approach a microwave circuit that makes use of lumped elements has been fabricated. A proof of concept is also
Antenna bandwidth broadening with a negative impedance converter
Cognitive radio (CR) has generated a lot of interest because of the promise of wide instantaneous bandwidths which will improve data rates. Current social trends suggest that CR nodes will ultimately be mobile and handheld. This produces a need for small wideband antennas. The Chu limit imposes a restriction on what is obtainable with passive matching. In this paper, it is shown how a negative imp