Techniques, devices and systems use pseudo-conductor materials as antennas to receive or radiate electromagnetic energy for communications and other applications. Methods of configuring an antenna can include, in some implementations, selecting a pseudo-conductor material having an electromagnetic constitutive property, wherein the electromagnetic constitutive property comprises a real part of the electromagnetic constitutive property that is greater than a corresponding imaginary part of the electromagnetic constitutive property; and forming the pseudo-conductor material into an antenna shape configured, upon being excited, to radiate emissions that satisfy a predefined antenna performance, such that the pseudo-conductor material formed in the antenna shape weakly guides an electromagnetic wave on the pseudo-conductor material using a leaky mode that is below cutoff to establish a field structure to radiate the emissions from the pseudo-conductor material that satisfy the antenna performance.

Pseudo-conductor antennas

A rotation sensor with a wide dynamic range is designed based on tapered U-shaped resonators. The proposed device is composed of a rounded microstrip transmission line that couples to two meandered resonators that are stacked on top of each other. By rotating the upper resonator, the overlapping area between the two resonators is increased causing a stronger coupling that shifts down the resonance frequency of the device. This frequency shift can be read out in the transmission response from which the rotation angle is determined. The operation principle of the sensor is explained in detail by using a circuit model. A sensor prototype is designed for the microwave frequency range and an experiment is presented for validating the proposed sensing approach. This sensing device is well suited for further miniaturization using microelectromechanical systems technology.

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Metamaterial-Inspired Rotation Sensor With Wide Dynamic Range

The constant evolution of wireless handheld devices together with the apparition of multiple wireless communication systems fosters the antenna community to design new radiating and measurements systems capable of satisfying the market demands. It is an object of the present paper to provide an overview of the evolution that wireless handheld technology has experienced in the last years. In this sense, a description of the evolution of wireless handheld devices, regulations, challenges in today’s smartphones, and handset characterization is reviewed. Finally, recent advances in antenna technology for wireless handheld or portable devices are presented.

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Advances in Antenna Technology for Wireless Handheld Devices

A radio frequency transmission apparatus includes a first elongated antenna element having a first feed end and a first aperture end. A second elongated element has a second feed end and a second aperture end. The second feed end is coupled to the first feed end. The first and second elongated antenna elements are positioned relative to each other to render a separation between the first antenna element and the second antenna element to increase from the first and second feed ends to the first and second aperture ends. The first and second antenna elements comprise pseudo-conductor material having an electromagnetic constitutive property having a real part greater than the corresponding imaginary part of the electromagnetic constitutive property.

Magnetic pseudo-conductor conformal antennas

A small-size coupled-fed loop antenna suitable to be printed on the system circuit board of the mobile phone for penta-band WWAN operation (824-960/1710-2170 MHz) is presented. The loop antenna requires only a small footprint of 15 x 25 mm2 on the circuit board, and it can also be in close proximity to the surrounding ground plane printed on the circuit board. That is, very small or no isolation distance is required between the antenna's radiating portion and the nearby ground plane. This can lead to compact integration of the internal on-board printed antenna on the circuit board of the mobile phone, especially the slim mobile phone. The loop antenna also shows a simple structure; it is formed by a loop strip of about 87 mm with its end terminal short-circuited to the ground plane and its front section capacitively coupled to a feeding strip which is also an efficient radiator to contribute a resonant mode for the antenna's upper band to cover the GSM1800/1900/UMTS bands (1710-2170 MHz). Through the coupling excitation, the antenna can also generate a 0.25-wavelength loop resonant mode to form the antenna's lower band to cover the GSM850/900 bands (824-960 MHz). Details of the proposed antenna are presented. The SAR results for the antenna with the presence of the head and hand phantoms are also studied.

On-Board Printed Coupled-Fed Loop Antenna in Close Proximity to the Surrounding Ground Plane for Penta-Band WWAN Mobile Phone

An inverted-FL antenna is proposal with a self-complementary structure. This unique design is realized by integrating an inverted-F antenna with a self-complementary structure and an inverted-L element. The proposed antenna with a volume of 10 times 10 times 45 mm3 achieves a constant impedance of 188 Omega without attaching a matching load required since a self-complementary antenna of an axially symmetric type has constant impedance. This antenna acquired broadband and multiband characteristics covering the GSM850/GSM900/DCS/ PCS/UMTS2100/UMTS2600 bands and the 2.5G/3.5G bands for Mobile-WiMAX by simulation and measurement.

Inverted-FL Antenna With Self-Complementary Structure

PROBLEM TO BE SOLVED: To obtain a microstrip antenna which can be balanced highly in axial ratio at a wide angle, broad band, and low loss. SOLUTION: A microstrip antenna is provided with an earth conductor 2, a parasitic conductor 7 which is laid separately from the conductor 2, a feeding conductor 3 which is laid between the conductors 2 and 7 so that a prescribed voltage may by applied across the conductors 2 and 3, and a wall-like member 5 which is arranged around an inter-conductor space demarcated by connecting the peripheral edge of the conductor 7 to that of the conductor 3 and made of a dielectric or conductive material.

Microstrip antenna and microstrip antenna substrate

We have proposed the inverted-FL antenna with a self-complementary structure. The proposed antenna realized a constant impedance property without attaching a matching load to the feed point even if it has finite structure. This antenna acquired the broadband and multi-band characteristics necessary for the required mobile phone services.

Inverted-FL antenna with self-complementary structure

PROBLEM TO BE SOLVED: To provide an antenna measuring device and a measuring method capable of measuring precisely excitation amplitudes and phases of each antenna element in consideration of amplitudes and phase errors of phase shifters and the amplitude and the phase error of a combined electric field in the operation state of all element antennas. SOLUTION: This device is equipped with an array antenna 5 including element antennas 41-4N and phase shifters 31-3N connected to the antennas respectively, a facing antenna 6 installed facing to the antenna, a transmitter 7 and a receiver 8 for radiating a signal from one side to the other side of the array antenna and the facing antenna and for receiving the radiated signal, a control device 1 for controlling the phase shifters based on the received output, an operation circuit 9 for measuring the amplitude and the phase change of the combined electric field of the array antenna from the received output when phase setting of each phase shifter is changed, and an operation circuit 10 for estimating the amplitudes and the phase errors of each phase shifter and the amplitude and the phase error of the combined electric field of the array antenna from the measurement result and for obtaining the relative amplitude and the phase of a radiated electric field relative to each element antenna.

Antenna measuring device and antenna measuring method

A design of a miniaturized tunable inverted-L antenna for mobile phones is proposed. The design integrates an inverted-L antenna with a split-ring resonator (SRR) structure. Although the use of SRRs to the inverted-L antenna achieves compact volume, the antenna's radiation efficiency rapidly decreases around the SRR's resonant frequency. The decrease is avoided by using a variable capacitance diode loaded on the SRR conductor. The proposed antenna has a compact volume of $1 \times 10 \times 50~{\hbox {mm}}^{3}~(0.5~{\hbox {cm}}^{3})$ , and can be tuned to the wide range, low frequency LTE700/GSM850/GSM900 bands (698–960 MHz). Simulation and measurement results showed the antenna obtains wideband and multi-band characteristics that enable it to cover the LTE700/GSM850/GSM900 and the LTE2600 bands.

Nobuyasu Takemura

Papers

Inverted-FL Antenna With Self-Complementary Structure

Microstrip antenna and microstrip antenna substrate

Inverted-FL antenna with self-complementary structure

Antenna measuring device and antenna measuring method

Tunable Inverted-L Antenna With Split-Ring Resonator Structure for Mobile Phones