The invention relates to a particular structure of high-frequency antenna, which comprises a support element (1) provided with a cylindrical coil conductor which forms a helix (2) On the support element (1) there is formed, for example by means of a conductive coating, the electrical parts of the antenna, such as the attachment points (3b) for the helix and for other parts, such as feeder lines (4), radiators (5) or impedance matching devices By varying the number and size of the helices (2), the number and form of the feeder lines (4) and radiators (5) and the quality of any impedance matching devices, it is possible without difficulty to obtain a very wide choice of different antenna structures The feeder lines and radiators extend, at least in part, within the helix

Combined structure of a helical antenna and a dielectric plate

A wideband radiating element including an input mechanism for receiving electromagnetic energy from a source and a balanced feeding mechanism extending from the input mechanism for transmitting the electromagnetic energy and for providing impedance matching over a range of frequencies. Finally, a dipole mechanism extending from the balanced feeding mechanism is provided for radiating the electromagnetic energy where the dipole mechanism has a shape to provide wide bandwidth impedance matching. In a preferred embodiment, an input mounting block is connected to the two opposing sides of a planar dielectric substrate. A balanced narrow conductor slot line extends from the input mounting block on both sides of the dielectric substrate to transmit the electromagnetic energy and to provide impedance matching over a frequency range of (0.5 to 18) GHz. The narrow conductor slot line is tapered to match the radiation resistance of a dipole element utilized to radiate the electromagnetic energy. The dipole element extends from the balanced narrow conductor slot line on both sides of the dielectric substrate with each wing having an expanded width for accommodating surface current of various distributions over the frequency range. The dipole element also includes an inner taper for radiating energy over the frequency range with the position of the dipole element relative to a ground plane being optimized to minimize radiation reflection.

Wide band dipole radiating element with a slot line feed having a Klopfenstein impedance taper

A resistor and method of forming the resistor as an annular resistor body between a conductive pad surrounding a through-hole in the PCB and a surrounding conductive layer, the annular resistor body being formed from a conductive material having a selected resistivity, the outer and inner perimeters of the annular resistor body preferably being substantially constant radii whereby the operative resistance of the annular resistor body may be simply determined from the radii of its outer and inner perimeters, an effective thickness of the annular resistor body and its resistivity, the annular resistor body more preferably being formed from a liquid precursor facilitating formation of conductive interconnections at its outer and inner perimeters.

Annular resistor coupled with printed circuit board through-hole

A dual-band octafilar helix antenna operational at two frequencies, while maintaining a relatively small package size. The dual-band octafilar antenna is manufactured by disposing radiators and a feed network onto a flexible substrate and forming the substrate into a cylindrical shape to obtain the helical configuration. The dual-band octafilar helix antenna includes four active radiators which are matched to a first frequency and disposed on a radiator portion of the flexible substrate. Four additional radiators, which may be either passive or active radiators, are matched to a second frequency, are also disposed on the radiator portion of the substrate and interleaved with the active radiators. At least one feed network is provided on a feed portion of the substrate that provides 0°, 90°, 180°, and 270° signals to active radiators. The sets of radiators and associated feed networks may be formed on opposing sides of a single substrate or on spaced apart layers in a multi-layered support substrate design.

Dual-band octafilar helix antenna

A thermistor using an RF-sputtered SiC film has been developed as a temperature sensor for cooking products. Since the SiC film has the advantage of being able to detect temperatures over the wide range of 0-500 degrees C with a good thermal stability, the thermistor can be applied not only to a conventional oven but also to a pyrolytic self-cleaning oven. Since the thermistor can detect surface temperatures with a rapid thermal response by contacting physically with an outer surface of an object, it can be also applied to a surface cooking top. The construction, electrical properties, and forming method of the SiC thin-film thermistor and applications to cooking products are described. >

SiC thin-film thermistors

The performance of microwave coplanar and other circuit boards is improved by providing local matching elements for adjusting the characteristic impedance of local transmission line segments to better match the input or output impedance of the particular devices to which they couple. This is accomplished by providing a conductive bridge over the active lead of the transmission line, thereby lowering its characteristic impedance. This is very useful for narrow transmission line segments needed to make contact to small active device and/or MMIC's and which otherwise exhibit a substantial impedance mismatch with such small elements.

Airbridge compensated microwave conductors

A high frequency transition (10) from a microstrip transmission line (57) to an MMIC coplanar waveguide (41) is provided. The microstrip transmission line (57) is representative of that typically encountered in a high frequency RF module on a first substrate (11). The MMIC coplanar waveguide (41) is representative of that encountered in low cost MMICs fabricated on a semiconductor substrate (56). An interface (15) couples the microstrip transmission line (57) to a mode converter (16). Mode converter (16) provides impedance mismatch compensation and coplanar waveguide propagation mode conditions for a connector coplanar waveguide (34) which connects from the first substrate (11) to the semiconductor substrate (56). An impedance transformer (40) provides additional impedance mismatch compensation on the semiconductor substrate (39) to complete the transition.

High frequency transition from a microstrip transmission line to an MMIC coplanar waveguide

A resistive element is formed on a printed circuit board using only printed circuit board fabrication techniques. A substrate having a bi-metallic cladding on one side of the substrate and a conductive metallic cladding on an opposing side of the substrate is used. A predetermined trace pattern is formed in the metallic cladding. Resistive elements are formed in the bi-metallic cladding opposing their desired locations in the trace pattern. The bi-metallic cladding consists of a resistive layer between the substrate and a second conductive layer. Tabs are etched in the second conductive layer, then resistors, which couple various tabs together, are etched in the resistive layer. Plated holes connect the tabs to desired locations in the trace pattern located on the opposing side of the substrate.

Method of forming and connecting a resistive layer on a pc board

A miniature microstrip dipole antenna is constructed on a high permitivity dielectric substrate for compactibility with microwave monolithic integrated circuit (MMIC) technology. The antenna comprises two dipole arms coupled to opposite faces of the substrate. The dipole arms are coupled to a microstrip transmission line through a tapered balun. The tapered balun comprises two conductors on opposite faces of the substrate which are coupled to corresponding dipole arms. The conductors are separated laterally (with respect to the width of the face of the substrate) a calculated distance, and are gradually tapered. This allows the balun to efficiently transform unbalanced signals at the microstrip transmission line to balanced signals at the plurality of dipole arms. Alternatively, the balun allows balanced signals at the dipole arms to be efficiently transformed to unbalanced signals at the microstrip transmission line. To achieve additional radiation directivity, a ground plane is coupled to and parallel with a back face of the substrate. By using a high dielectric substrate, the cavity formed between the substrate and the ground plane is relatively very shallow.

High permitivity dielectric microstrip dipole antenna

A complimentary switched amplifier transceiver (10) is provided which offers performance advantages and reduces system complexity over conventional half-duplex transceivers by using complimentary switched amplifiers for eliminating switches. Power output to a channel transition (31) from a transmit amplifier (26) is not degraded by a switch insertion loss in a transmit mode. Receiver noise figure is not degraded due to the switch insertion loss from the channel transition (31) to a receive amplifier (27). Switch devices and their associated control lines are eliminated, reducing circuit complexity for complimentary switched amplifier circuits such as a combined amplifier switch (12) and a first bi-directional amplifier (22).

Ronald F. Kielmeyer

Papers

Airbridge compensated microwave conductors

High frequency transition from a microstrip transmission line to an MMIC coplanar waveguide

Method of forming and connecting a resistive layer on a pc board

High permitivity dielectric microstrip dipole antenna

Complimentary switched amplifier transceiver system