Jose Luis Masa-Campos

Dual Linear/Circular Polarized Plannar Antenna with Low Profile Double-Layer Polarizer of 45º Tilted Metallic Strips for WiMAX Applications

This work is supported by Madrid Region Government and the Autonoma University of Madrid, Ref. CCG07-UAM/TIC-1794 & Ref. CCG08-UAM/TIC-4315.

Novel Four Cross Slot Radiator With Tuning Vias for Circularly Polarized SIW Linear Array

A substrate integrated waveguide (SIW) linear array is presented with a new circularly polarized (CP) element. The single radiator consists of four cross tilted slots. In addition, a pair of tuning metallic vias is included to improve the reflection of longest slots. A 16-element antenna prototype with -26-dB Taylor distribution and 1.5% residual power was designed, manufactured and measured to verify the new slot performance in an array configuration. A 17-dB peak gain, 1.86-dB axial ratio and 80% radiation efficiency were experimentally achieved at 17 GHz. A 3% usable bandwidth was obtained owing to frequency main beam tilt dispersion.

SHORT RANGE PROPAGATION MODEL FOR A VERY WIDEBAND DIRECTIVE CHANNEL AT 5.5 GHZ BAND

In this work, the propagation loss of three short range directive channels at 5.5GHz is measured using difierent directive antennas and a Vector Network Analyzer (VNA). Results are given for a channel bandwidth of 300MHz which will be the future channel bandwidth of IEEE 802.11 ac system. It has been noted that the multipath induced fading tends to have Normal Distribution at low distance between the transmitting and the reception antennas. At higher distances, it tends to have Normal distribution plus Rayleigh one. Channel Impulse response (CIR) is also measured indicating that the main contribution is due to the direct ray and the one re∞ected from the ∞oor. The human being obstruction causes an extra propagation loss of 2 to 10dB depending on its distance from the transmitting antenna.

Linear Patch Array Over Substrate Integrated Waveguide for Ku-Band

A linearly polarized patch array with direct probe feed over substrate integrated waveguide (SIW) network (LP-PASIW) for Ku-band is presented. A double-stacked microstrip patch structure has been used as radiating elements. Internal SIW coupling patches are placed inside the SIW to obtain the desired radiation pattern. The internal coupling and external radiating patches are connected by means of copper vias. A mutual coupling model is also proposed to adjust the radiation and reflection properties of the array. An antenna prototype has been manufactured and measured. At 17.7 GHz, 16 dBi and 80% peak gain and efficiency values are obtained. Although a 10% reflection bandwidth (17-18.6 GHz) is achieved, the usable bandwidth is reduced to 3% due to array beam tilt dispersion.

Monopulse waveguide patch array antenna in 37 GHz band

We present a circularly polarized patch array in 37 GHz frequency, within a narrowband application (less than 1%) for signal detection. The designed array needs to have some specific requirements related to its radiation pattern (monopulse configuration to identify the input direction of a signal), circular polarization (RHCP) with an axial ratio under 3 dB, low sidelobe level in the sum pattern, and high gain. Taking into account this last requirement and the working frequency a lossless scheme is needed, and the waveguide feed provides it. The coupling mechanism from the waveguides to the radiating elements is made by inside microstrip lines. The radiating element is a modified circular patch easily manufactured on printed circuit.

Omnidirectional conformal patch antenna at S-band with 3D printed technology

This work has been supported by the Spanish Government, Ref. TEC2013-47106-C3-2-R (Project TECOAMP) and Madrid Region Government, Ref. S2013/ICE-3000 (Project SPADERADAR).

Computer Automated Design of an Irregular Slotted Waveguide Array for Ku-Band

A computer automated design methodology to synthesize a progressive wave array antenna is presented. The proposed method is based on the generalized-scattering matrix and spherical wave expansion analysis of the array. Mutual coupling effects between radiating elements are inherently considered in the design process. A linearly polarized 24-element irregular slotted array antenna at Ku-band is presented to describe the proposed computer automated design methodology. A prototype has been manufactured to experimentally validate the antenna performance. At the design frequency (17 GHz), 15.9 dB realized gain and 97% efficiency (excluding aluminum losses) values are achieved. Although the array is designed at a single frequency, it shows an overall experimental 7% usable bandwidth.

Materials Insertion Loss at 2.4, 3.3 and 5.5 GHz Bands

The insertion loss of different materials is measured at 2.4, 3.3 and 5.5 GHz bands. Directive antennas with a nominal gain of 19 dB are used in the measurement campaign. The height of the antennas has been selected to have the minimum possible reflection from around surfaces. Metallic door with porthole window, metallic grid, glass window, human beings and tree’s insertion loss are measured. The metallic grid presents a band pass filter function with a resonance frequency between 3.2 to 3.3 GHz. Other materials have an insertion loss that increases with the increment of the operating frequency.

Development of Radial Waveguide Dividers with Large Number of Ports

Power division/combination is a very important function for achieving high-performance power amplification in microwave and millimeter-wave systems, allowing the use of simpler individual amplifiers to provide microwave/millimeter wave high power signals. In this paper we address the development of divider/combiners in waveguide technology for large number of ports. Radial waveguide dividers will be studied, starting from the S-parameters representing the N-port waveguide junction, and ending with the full-wave simulations. Two different designs in this technology are studied. The experimental evaluation will come from a prototype at Ku-band, fabricated and tested in order to validate the design.

Slotted waveguide antenna design by segmented simulation and multi-objective genetic algorithm

A progressive-wave antenna automated design technique is presented in this work. By means of a simulation method based on spherical wave expansion and generalized scattering matrix, full-wave analysis of a slotted waveguide array can be efficiently performed. Since coupling effects are considered in the simulation, a final antenna design can be obtained without any further modification required on it. In order to achieve such design, a multi-objective optimization based on Nondominated Sorting Genetic Algorithm Version III (NSGA-III) state-of-the-art genetic algorithm is carried out. At the working frequency of 17 GHz, final design provides a 16.6 dBi gain, Side-Lobe Levels lower than −18.3 dB and a 0.6% power waste at the output port. A −15-dB matching bandwidth of an 8.8% is obtained. The results have been validated with commercial-software simulations.