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Full-Text Articles in Engineering
Measurement Of Orientation And Distance Change Using Circularly Polarized Uwb Signals, Janusz Przewocki, Max Ammann, Adam Narbudowicz
Measurement Of Orientation And Distance Change Using Circularly Polarized Uwb Signals, Janusz Przewocki, Max Ammann, Adam Narbudowicz
Articles
The article proposes methodology to use circularly polarized (CP) ultra-wideband (UWB) signals for simultaneous measurement of orientation and distance changes between transmitter and receiver. The proposed technique uses the rotational Doppler effect on CP pulsed communication. The amplitude of a CP signal is immune to polarization misalignment in the presence of rotation; however, the phase is subjected to a frequency-invariant shift proportional to the rotation angle. This significantly distorts the pulse shape in the time domain and can be used for the measurement of the rotated angle. By combining the technique with the well-known localization capability of UWB systems, one …
Design Method For Wideband Circularly Polarized Slot Antennas, Adam Narbudowicz, Matthias John, Vit Sipal, Xiulong Bao, Max Ammann
Design Method For Wideband Circularly Polarized Slot Antennas, Adam Narbudowicz, Matthias John, Vit Sipal, Xiulong Bao, Max Ammann
Articles
A compact ultrawideband (UWB) circularly polarized (CP) slot antenna is proposed with a methodology for automated reoptimization for packaging with proprietary devices. The slot structure employs a dual-feed with an integrated compact UWB phase shifter. The design process involves an advanced optimization algorithm and demonstrates the use of spline curves for generation of CP signals. These allow easy optimization, while preserving phase coherency across a wideband. The prototyped antennahas a CP bandwidth of 54% (from 3.2 to 6.1 GHz).
Contactless Measurement Of Angular Velocity Using Circularly Polarized Antennas, Vit Sipal, Adam Narbudowicz, Max Ammann
Contactless Measurement Of Angular Velocity Using Circularly Polarized Antennas, Vit Sipal, Adam Narbudowicz, Max Ammann
Articles
An innovative method to measure the angular velocity using circularly polarized antennas is proposed. Due to the properties of circular polarization, the angular velocity is frequency modulated (FM) on a wireless carrier. This enables a low-cost precise continuous measurement of angular velocity using a standard FM demodulator. The hardware can be easily adapted for both high and low angular velocity values. The precise alignment angle between the antennas can be determined if the initial antenna orientation is known. The angular error is shown to be
Using Near-Field Coupled Circularly Polarized Antennas As Frequency Independent Variable Phase-Shifters, Vit Sipal, Adam Narbudowicz, Max Ammann
Using Near-Field Coupled Circularly Polarized Antennas As Frequency Independent Variable Phase-Shifters, Vit Sipal, Adam Narbudowicz, Max Ammann
Articles
This paper introduces a novel concept of frequency-independent variable phase-shifters. It is based on the use of circularly polarized (CP) antennas coupled in the near-field. For transmission between two CP antennas in the far-field, a rotation around the boresight axis produces a phase change in the transfer function. This concept is exploited and validated also for near-field coupling between two CP antennas. Therefore, two close-coupled CP antennas can act as a adjustable phase-shifter with the phase-shift controlled by the angle between the structures. The bandwidth depends on the CP bandwidth of the antenna. This concept is valuable for future phase-shifters …
Dual Circularly-Polarized Patch Antenna Using Even And Odd Feed-Line Modes, Adam Narbudowicz, Xiulong Bao, Max Ammann
Dual Circularly-Polarized Patch Antenna Using Even And Odd Feed-Line Modes, Adam Narbudowicz, Xiulong Bao, Max Ammann
Articles
This paper proposes a new patch antenna with dual circularly polarized capability at 2.575 GHz. The design exploits the even and odd modes in a coplanar waveguide transmission line and enables simultaneous right- and left-handed circular polarization, with two individual excitation ports. A patch antenna is fed by multimode transmission line and the advantages and disadvantages are discussed. A prototyped antenna realized up to 20 dB isolation between ports with S21 < -10dB bandwidth of 87 MHz. Realized gains for the two modes of operation are 5.77 and 7.23 dBic. The proposed structure is compact and easy to manufacture.
Dual-Band Omnidirectional Circularly Polarized Antenna, Adam Narbudowicz, Xiulong Bao, Max Ammann
Dual-Band Omnidirectional Circularly Polarized Antenna, Adam Narbudowicz, Xiulong Bao, Max Ammann
Articles
A dual-band omnidirectional circularly polarized antenna is proposed. The antenna comprises back-to-back microstrip patches fed by a coplanar waveguide. A very low frequency ratio of 1.182 has been achieved, which can be easily tuned by adjusting four lumped capacitors incorporated into the antenna. An analysis of the omnidirectional circular polarization mechanism as well the dual band operation is provided and confirmed by numerical and experimental data. Key parameters to tune the resonant frequencies and the axial ratio have been identified. The prototype antenna provides omnidirectional circular polarization in one plane with cross polar isolation better than 12 dB for both …
Microstrip-Fed Wideband Circularly Polarized Printed Antenna, Xiulong Bao, Max Ammann, Patrick Mcevoy
Microstrip-Fed Wideband Circularly Polarized Printed Antenna, Xiulong Bao, Max Ammann, Patrick Mcevoy
Articles
A wideband circularly-polarized printed antenna is proposed, which employs an asymmetrical dipole and a slit in the ground plane which are fed by an L-shaped microstrip feedline using a via. The proposed antenna geometry is arranged so that the orthogonal surface currents, which are generated in the dipole, feedline and ground plane, have the appropriate phase to provide circular polarization. A parametric study of the key parameters is made and the mechanism for circular polarization is described. The measured results show that the impedance bandwidth is approximately 1.34 GHz (2.45 GHz to 3.79 GHz) and the 3 dB axial ratio …