Abstract: Electrically small shortened HF and VHF microstrip cylindrical antenna with a reduced antenna length are provided. The electrically small shortened HF and VHF microstrip cylindrical antennas are constructed with concentric, ceramic cylinders having copper coating that operate at low frequencies. The concentric, ceramic cylinders alternate with concentric copper layers in a corrugated alternating structure where certain copper layers function as the ground plane and others function as part of the radiating patch providing both a shortened antenna length and the ability to operate efficiently at low frequencies. It is now possible to provide a ten-fold size reduction with these antennas.

Abstract: A multiple band electrically small compact planar microstrip antenna at VHF and UHF frequencies is provided that permits both a considerably abbreviated antenna length and significantly high efficiency antenna performance. The multiple band electrically small compact planar microstrip antenna advantageously positions a narrow radiating strip and a group of unequally dimensioned radiating members on a microstrip dielectric substrate that is stacked on a ground plane. The unequally dimensioned, or unlike, radiating members are separated by at least one gap and cause the antenna to resonate at a number of different frequencies instead of a single frequency as the prior art microstrip antenna. The multiple band electrically small compact planar microstrip antenna also innovatively filters unwanted signals at other frequencies because of the narrowband nature of each band.

Abstract: A spectrum analyzer includes a resonator board that in turn has a substrate and a plurality of resonators. Each resonator may include a first segment that includes a first segment discontinuity and that may also define a boundary and a second segment that has a second segment discontinuity. The second segment may be spaced from the first segment and wherein the second segment is disposed within the boundary defined by the first segment. The resonator board may also include a plurality of wires each of which may be generally parallel to each other and each having a resonator interposed therebetween.

Abstract: A spectrum analyzer includes a resonator board that in turn has a substrate and a plurality of resonators. Each resonator may include a first segment that includes a first segment discontinuity and that may also define a boundary and a second segment that has a second segment discontinuity. The second segment may be spaced from the first segment and wherein the second segment is disposed within the boundary defined by the first segment. The resonator board may also include a plurality of wires each of which may be generally parallel to each other and each having a resonator interposed therebetween.

Abstract: An electrically small wideband circularly polarized single layer compact microstrip antenna that permits a substantial reduction in antenna size is provided, by stacking a semicircular radiating arch on a dielectric substrate and a conductive ground plane that permits both a considerably reduced antenna length and significantly high efficiency antenna performance. The radiating arch is composed from a group of arc-shaped segments that are each separated by a gap, with one segment having an opening allowing a connector center probe to protrude upwards. In the preferred embodiment, the arc-shaped segments are arranged into a semicircle on the top surface of the dielectric substrate. Other embodiments include an array antenna and a method for decreasing a wideband circularly polarized compact microstrip antenna with a given length, AL.

Abstract: A folded multilayer electrically small compact microstrip antenna provides an electrically small antenna for the lower frequencies. The folded multilayer electrically small compact microstrip antenna employs a folding radiation strip is divided into segments and is interleaved with a multiple layered microstrip dielectric substrate and a means for a conductive ground plane having a number of conductive branches. A narrow portion of the radiating strip, a coaxial connector, and a first conductive branch are positioned so that a wide portion of the radiating strip provides a given impedance and the narrow portion causes a reduced effective impedance at a junction point. The reduced impedance provide a shortened antenna length that operates at VHF and HF frequencies. The different embodiments of this invention's folded multilayer electrically small compact microstrip antenna include 2, 3 and 5 dielectric layers.

Abstract: An electrically small planar tunable microstrip antenna is provided by stacking a radiating element, microstrip dielectric substrate and a ground plane, and coupling the ground plane to a means for tuning. The electrically small, compact, planar tunable microstrip antenna operates at HF and VHF frequencies. The microstrip dielectric substrate is composed of a ferrite or ferrite-ferroelectric composite material having a relative dielectric constant similar to a relative magnetic permeability forming a permittivity to permeability ratio of between about 1:1 and about 1:3. The ground plane is coupled to a means for tuning. In the ferrite-ferroelectric embodiment, the present invention provides an antenna length that is substantially shortened to approximately 1% of the length of a monopole antenna or conventional microstrip antenna with tuning accomplished by a multi-turn coil mechanism.

Abstract: The present invention is an antenna comprising a microstrip having upper and lower layers for producing leaky wave radiation. Circularly shaped patches are located on the two layers for circularly polarizing the leaky wave radiation. The present invention provides a microstrip antenna that can produce wideband, circularly polarized radiation. The antenna, therefore, is a compact, low cost, rugged, conformal, planar, and circularly polarized microstrip antenna. The antenna combines the advantages of wideband circularly polarized radiation with the advantages of lightweight, low profile, low cost, and planar microstrip antennas.

Abstract: A first and a second conductive patch of a compact planar microstrip antenna are connected at a junction point to shorten the length of the impedance transition from the center point, where the wave impedance vanishes, to the patch edge, where the impedance becomes very large. The second conductive patch is wider than the first conductive patch and one end of the first conductive patch is shorted with the ground plane. The effective impedance to be satisfied by the narrower strip at the junction is greatly reduced by the presence of the junction of two different patches, which decreases the size of the antenna greatly for the required frequency range.

Abstract: A first and a second conductive patch of a compact cylindrical microstrip antenna are connected at a junction point to shorten the length of the impedance transition from one edge, where the wave impedance vanishes, to the other patch edge, where the impedance becomes very large. The second conductive patch is wider than the first conductive patch and one end of the first conductive patch is shorted with the ground plane. The effective impedance to be satisfied by the narrower strip at the junction is greatly reduced by the presence of the junction of two different patches, which substantially decreases the size of the antenna at a given operation frequency.

Abstract: A compact wideband leaky-wave excitation microstrip antenna is provided by a group of microstrip patches disposed on a top region of a dielectric substrate stacked on a conductive ground plane. The top region of the dielectric substrate and the dielectric substrate can be composed of either the same or different dielectric materials. A means for feeding an RF signal, which can be a center feed pin, that normally touches the top conducting patch is electrically isolated from the radiating patches. This arrangement confines the feed current within the probe pin to give an increased input resistance. The compact wideband leaky-wave excitation microstrip antenna permits significant reductions in antenna size, resulting in microstrip antennas with a smaller surface area.

Abstract: The present invention is a microstrip antenna which produces ultrawide band leaky wave radiation. The antenna produces leaky wave radiation, then trs the leaky wave radiation to produce an ultrawide bandwidth. The antenna includes tapered metal patches which taper the radiation. The antenna gives an ultrawide bandwidth performance of greater than a 4:1 ratio.

Abstract: A microstrip antenna providing circularly polarized radiation formed by two layered cavities with two rectangular conductive patches. A first cavity s formed by a ground plane and a first rectangular conductive patch having a lateral dimension and coupling holes placed therein. A second cavity is formed between the first rectangular conductive path and a second rectangular conductive patch having a longitudinal dimension. The longitudinal dimension of the second rectangular conductive patch is essentially equal to the lateral dimension of the first rectangular conductive patch. The second rectangular conductive patch is coupled through the coupling holes to the first rectangular conductive patch, resulting in circularly polarized radiation. The circularly polarized antenna can easily be manufactured using conventional microstrip techniques. Additionally, bandwidth and power are improved.

Abstract: A wideband leaky-wave microstrip antenna having two elongated rectangular nductive patches separated by a gap on a first dielectric material and an elongated rectangular conductive coupling patch on a second dielectric material placed over the gap. The selective placement of the conductive patches and the gap formed thereby permits impedance matching resulting in a leaky-wave propagation mode. Non-radiating modes of propagation are not excited, thereby enhancing the leaky-wave mode of propagation causing radiation. This results in a relatively wide bandwidth of operation that has a main beam that is scannable as a function of frequency. The bandwidth increases substantially as the dielectric constant approaches one. The planar construction contributes to design flexibility and ease of manufacture and has many applications military and commercial communication systems.

Abstract: A circularly polarized antenna is described having a ground plane and spa conductive patches parallel to it forming lower and upper cavities. The lower cavity is excited by a coax introduced at an impedance matching point in the ground plane, and the upper cavity is energized by apertures in the middle patch. The sides of the lower cavity from which radiation does not emanate are shorted to the ground plane, and the sides of the upper cavity from which radiation does not emanate as shorted to the middle patch.

Abstract: A planar dual band antenna comprising three superimposed dielectric layers, ground plane on one external surface, a conductive patch on the other and parallel conductive strips at the interface of dielectric layers that is closer to the patch. The dielectric constant of the middle layer is different from that of the two other layers.

Abstract: A dual-frequency microstrip antenna has three strips of bare low-dielectric aterial alternating with two strips of copper-clad (one side) high-dielectric material bonded close together on a copper plate having a feed inserted therethrough. A copper-claded layer (one side) low-dielectric material is placed over the five strips and bonded simultaneously. The inner strips separate the region of high-dielectric constant from the region of low-dielectric constant. The microstrip antenna is considered to be a lossy resonating cavity enclosed by a perfect electric conductor and by a perfect magnetic conductor.

Abstract: A microstrip antenna capable of dual-frequency operation. The antenna comprises a microstrip having a thin, rectangular metal strip that is supported above a conductive ground plane by two dielectric layers which are separated by an air gap or other lower dielectric constant material. Conducting side walls and a rear wall extend between the ground plane and the strip. The ground plane, the strip, the walls and an opening at the front cooperate to form a rectangular resonant cavity. In essence, the cavity is surrounded by conducting surfaces except for the front opening and a small opening in the ground plane that accommodates an antenna feed. The front opening of the cavity functions as an antenna aperture through which the antenna transmits and/or receives energy. The antenna feed is a coaxial transmission line that provides a means for coupling the antenna to an external circuit. The spaced dielectric layers and the air gap produces higher-order modes which causes dual frequencies.

Abstract: A mm wavelength power combiner comprising an open resonator comprising a r of confronting concave reflectors which can be either spherical or parabolic. The resonator dimensions are many times the wavelength of the energy sources to be combined. A plurality of mm wave energy sources are applied to the resonator in such a way that the great majority of the energy bounces back and forth between the reflectors near the axis thereof in the fundamental or Gaussian mode. The design minimizes multimoding and diffraction losses.