Spiral antenna 2-18 ghz amplifier
The antenna has an array of spiral antennae with spiral arms 11, 12, 21, 22 and inter-digital electrical feeders 3, 4. The spiral antenna array is illuminated with laser light 6 using a lens array 5. The entire spiral antenna array comprises two different forms of spiral antennae arranged in antenna rows 1, 2. The spiral antennae of the rows possess same winding directions and different numbers of windings.
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ISR SIGINT/ELINT Antenna Products
The antenna has an array of spiral antennae with spiral arms 11, 12, 21, 22 and inter-digital electrical feeders 3, 4. The spiral antenna array is illuminated with laser light 6 using a lens array 5. The entire spiral antenna array comprises two different forms of spiral antennae arranged in antenna rows 1, 2. The spiral antennae of the rows possess same winding directions and different numbers of windings. Focal points of individual flat-convex lenses of the lens array are found at a surface between beginnings of the spiral arms in a center of the antenna rows.
The lens array consists of glass or organic material. The The invention relates to a photoconductive antenna for radiation or for receiving terahertz radiation. When Terahertz radiation becomes electromagnetic radiation in the frequency domain from about 0. Since there are molecular vibrations in the frequency range of terahertz radiation Numerous substances can be detected by absorption spectroscopy in the Terahertz area the investigation of substances done and also the detection of certain chemical compounds are performed.
Objects can also material-specific by means of terahertz radiation in transmission or reflection. There is therefore a scientific and technical Interest in cost-effective and efficient emitters and detectors for terahertz radiation.
A photoconductive terahertz antenna consists essentially of a high-resistance semiconductive layer having a short relaxation time of the charge carriers in the range of picosecond, which is applied to a likewise high-resistance substrate and on an electrically conductive antenna structure, for example in the form of a dipole or a spiral antenna with a Gap is arranged as an interruption in the center of the antenna. For radiating or detecting terahertz radiation, the semiconductor layer in the gap of the antenna is irradiated with short laser pulses.
This creates an electric gap in the antenna Field followed by the free carriers generated by the optical pulse. In the acceleration phase of the charge carriers becomes electromagnetic Radiation emitted in the terahertz range. Because of the low relaxation time the charge carrier The resulting electric current is then stopped very quickly, which in turn leads to the emission of terahertz radiation. To the Detection of terahertz radiation is applied to the photoconductive antenna a power amplifier connected.
A current is then measurable, if at the antenna an electrical Field of terahertz radiation is applied and at the same time a laser pulse in the semiconducting gap the antenna free charge carriers generated. As for the generation of terahertz radiation required laser power is expensive, it comes in the design of photoconductive emitter antenna on it, high efficiency at to achieve the conversion of laser power to terahertz power.
In addition to simple dipole antennas patents US 5 A. JP A. CA 2 JP 06 A. KR 10 A. However, when such antennas are used to generate terahertz radiation, the radiated power is limited by the fact that the gap of the antenna can only be irradiated with a low optical power in order to avoid destruction of the antenna due to local thermal stress.
For the same reason, the voltage applied to the gap of the antenna is also limited. Derartige Antennenanordnungen sind jedoch nicht zur Emission oder zum Empfang von Terahertz-Strahlung geeignet. For passive applications, antenna arrays of spiral antennas with different spacings and sizes have been proposed. Antenna arrays of dipole or spiral antennas, some with a combination of different individual antennas are disclosed in the patent US 5 A for broadband absorption of electromagnetic waves in the frequency range of about GHz, to realize a non-radar-reflecting surface.
However, such antenna arrangements are not suitable for emission or reception of terahertz radiation net. In order to increase the radiated power and the directional characteristic, in the case of a conventional feed of the transmitting antennas with a high-frequency generator, arrays of antennas can be used, which in the case of phased arrays also have an adjustable emission direction patents US Pat.
US 6,, B2. US Pat. CA 7C. JP 58 A. However, for the emission of terahertz radiation antennas can not be interconnected in the same way as is common in high-frequency technology, because of the electrical supply lines of terahertz antennas no high frequency, but a DC voltage is supplied, the only by the irradiation of the gap the antenna leads to the generation of a terahertz pulse.
However, a simple array of individual antennas interconnected with parallel electrical feed lines in the form of an interdigital structure results in cancellation of the terahertz signal due to the different phase of adjacent antenna arrays and is therefore not appropriate. In order to avoid destructive interference in the interconnection of terahertz dipole antennas, an interdigital finger structure of the feeders has been proposed, in which every other finger structure is covered with a stimulating laser light-impermeable layer Patent DE 10 A1.
This ensures that the terahertz waves radiated between the fingers of the interdigital structure have a uniform polarization direction and phase and overlap constructively in the far field. Although using such a terahertz radiation source with partially covered interdigital structure achieves significantly greater terahertz radiant powers than with a simple dipole antenna, the efficiency of such antennas is limited for the following two reasons: First, more than half of the laser power is due to irradiation of the covered ones Antenna areas are lost unused and second, less than half of the antenna area is used for the emission of terahertz radiation.
The loss of about half of the laser power can be with that in the patent DE 10 B3 proposed interdigital antenna structure with a lens array for illumination are avoided.
However, this antenna arrangement also has the disadvantage that the antenna area used for the emission of the terahertz radiation corresponds to only about half of the total antenna area, because only every second interspace of the interdigital finger structure is used for the radiation to ensure the phase coincidence of the emitted terahertz radiation can. Dadurch wird eine destruktive Interferenz der emittierten Terahertz-Strahlung vermieden siehe A proposal to use by means of a suitably shaped lens array both the entire laser power and the entire antenna surface for the emission of terahertz radiation is in the patent JP A described.
For this purpose, a specially shaped lens array is described which illuminates an interdigitated antenna structure by means of a structured phase plate in such a way that every second space between the fingers is illuminated with the exciting laser pulse at a later time.
This avoids destructive interference of the emitted terahertz radiation see However, this increases the terahertz pulse duration by at least half a period or results in two separate terahertz pulses, which leads to a limited usability of such a radiation source in a terahertz time-domain measuring system.
In addition, the technical complexity for the production of the lens array is very high together with the phase plate, which increases the cost of this arrangement.
Es wird vorgeschlagen, das photoleitende Halbleitermaterial der Antenne auf einem elektrisch isolierenden Substrat aufzubringen und dieses Material in jedem zweiten Zwischenraum der Fingerstrukturen zu entfernen. Another approach to avoiding the destructive interference of terahertz radiation generated in interdigital antennas is in the patent DE 10 A1 specified. It is proposed to apply the photoconductive semiconductor material of the antenna on an electrically insulating substrate and to remove this material in every second interspace of the finger structures.
As a result, the terahertz radiation is generated only in every second interspace of the interdigital antenna and superimposed constructively.
The disadvantages of this arrangement, in addition to the complicated manufacturing technology of the antenna is that only a portion of the laser light is used and only every other space of the interdigital antenna is used for the radiation. Of the Invention is based on the object, a photoconductive antenna in the form of an array of individual antennas for radiation or to indicate the reception of terahertz radiation, in which the main part the entire antenna surface for the Radiation or the reception of terahertz radiation can be used.
This is intended to ensure that such Antenna when used as a transmitting antenna a higher terahertz radiation power as a known large area photoconductive Antenna emits and when used as a receiving antenna, a larger current than provides the known photoconductive antennas. According to the invention this Task with the photoconductive antenna for radiation or for Receiving terahertz radiation with the features of the claim 1 solved.
The invention claim advantageously further developing features Subject of the dependent claims and the description with reference to the embodiments with the associated Illustrations. The The invention will be explained in more detail below with reference to three exemplary embodiments. Die photoleitende Antenne besteht aus einem Array von Spiralantennen, die in Reihen zwischen elektrischen Speiseleitungen 3 , 4 angeordnet sind.
Die elektrischen Speiseleitungen 3 , 4 besitzen die Form einer interdigitalen Finger-Struktur. Die Spiralantennen werden mittels eines Linsenarrays 5 mit Laserlicht 6 bestrahlt. The photoconductive antenna consists of an array of spiral antennas arranged in rows between electrical feeders 3. The electrical supply lines 3. The spiral antennas are made by means of a lens array 5 with laser light 6 irradiated.
Das gesamte Array von Spiralantennen besteht aus zwei unterschiedlichen Formen von Spiralantennen, die jeweils eine erste Antennenreihe 1 und eine zweite Antennenreihe 2 bilden.
Die Spiralantennen der ersten Antennenreihe 1 und der zweiten Antennenreihe 2 sind jeweils zwischen den interdigitalen elektrischen Speiseleitungen 3 , 4 abwechselnd angeordnet. The entire array of spiral antennas consists of two different forms of spiral antennas, each with a first antenna array 1 and a second antenna array 2 form.
The spiral antennas of the first antenna array 1 and the second antenna array 2 are each between the interdigital electrical supply lines 3. The spiral antennas of the first antenna array 1 and the second antenna array 2 have the same sense of winding, but differ in the number of turns by half a turn. The focal points of the individual lenses of the lens array 5 are located on the surface of the photoconductive antenna between the beginnings of the two spiral arms Die Spiralantennen der ersten Antennenreihe 1 und der zweiten Antennenreihe 2 besitzen logarithmische, winkelkonstante Spiralarme 11 , 12 , 21 , Die Breite der Spiralarme ist bei jedem Radius gleich ihrem Abstand.
Solche logarithmische Spiralantennen strahlen besonders breitbandig ab. The spiral antennas of the first antenna array 1 and the second antenna array 2 have logarithmic, constant-angle spiral arms The width of the spiral arms is equal to their distance at each radius. They are therefore self-similar. Such logarithmic spiral antennas radiate particularly broadband. Its lower limit frequency is determined by the outer and its upper limit frequency by the inner radius.
In the first embodiment, the inner radius of the spiral antennas of the antenna rows 1 and 2 same, which causes a uniform upper cutoff frequency of the entire antenna array. Because of the larger radius of the spiral antennas of the first antenna array 1 These have a lower lower cutoff frequency than the spiral antennas of the second antenna array 2 ,.
Durch diesen Unterschied einer halben Windung wird erreicht, dass alle Antennen phasengleich abstrahlen und sich im Fernfeld eine konstruktive Interferenz ergibt. The larger spiral antennas of the antenna rows 1 have one turn and the smaller spiral antennas of the antenna rows 2 own a half turn. This difference of half a turn ensures that all antennas radiate in phase and results in the far field constructive interference.
Der wesentliche Erfindungsgedanke besteht darin, dass der Unterschied zwischen den Windungszahlen der Spiralantennen benachbarter Reihen genau eine halbe Windung ist. The The invention is not limited to the spiral antennas are logarithmic and have a half or one turn. The essential idea of the invention is that the difference between the numbers of turns of the spiral antennas of adjacent rows exactly half a turn. Consequently, for example, too a broadband array with logarithmic spiral antennas of one turn and one and a half turn, respectively each antenna array can be put together or it can Archimedean Spiral antennas are used, either round or square accomplished are.
The spiral antennas emit a circularly polarized terahertz field, the direction of rotation of the field being determined by the direction of rotation of the spiral arms In the embodiment shown, the spiral antennas of the antenna rows 1 and 2 and the lenses of the lens array disposed above 5 arranged in the form of a hexagonal grid to achieve optimum utilization of the available area of the photoconductive antenna.
The invention is not limited to such an arrangement, but the spiral antennas of the antenna rows 1 and 2 can also be arranged differently, for example in the form of a rectangular or square grid. The lens array 5 consists of a transpa pension plate made of glass 9 , in the surface of which the lens shapes are impressed. In the first embodiment, the spiral antennas of the antenna rows 1 with one turn a larger diameter than the spiral antennas of the antenna rows 2 that have only half a turn.
Accordingly, the distances of the electrical supply lines 3. Die Zentren der Spiralantennen befinden sich jeweils in der Mitte zwischen den elektrischen Speiseleitungen 3 und 4. In the schematic representation of the cross section through the first embodiment of the photoconductive antenna for emitting or receiving terahertz radiation in 2 is visible as the laser light 6 by means of the lens array 5 of glass on the centers of the spiral antennas of the antenna rows 1 and 2 is focused.
The centers of the spiral antennas are located in the middle between the electrical supply lines 3 and 4 ,.
Bei den bekannten interdigitalen Antennenarrays kann nur jeder zweite Zwischenraum zwischen den elektrischen Speiseleitungen mit Antennen genutzt werden, um eine destruktive Interferenz zu vermeiden.
The advantage of the arrangement according to the invention over the known prior art is that each space between the electrical feed lines 3. In the known interdigital antenna arrays only every second space between the electrical feed lines can be used with antennas to avoid destructive interference.
List of Accepted Papers
You can use the search feature of your web browser to find your paper number. Notifications to all authors have also been sent by email. If you have not received your notification of the results by email, please contact us at papers apsursi. Support: webmaster apsursi. A Compact Circularly Polarized 2. A T-shaped defected ground structure for decoupling circularly polarization microstrip antenna array. Analysis of a fractal small antenna using shorting post and the social spider optimization algorithm.
2 GHz Frequency Generation
Back to Profile page. Oral presentation for an academic conference. Improvement of transmission isolation by controlling port directions of loop arrays. Suppression of interference wave using resistors for OAM multiplexing communication with loop arrays. Analysis of received currents on loop antenna array for plane wave incidence. Analysis on orbital angular momentum of field radiated by loop antenna for OAM Communication. Hiroshi Mizutani, Kazuhiko Honjo. An investigation on doubling multiplicity for OAM communication using circular loop antennas. Microwave Workshops
Coaxial waveguide antenna
Our LX series cavity backed spirals are broadband antennas designed for EMC, surveillance, direction finding, telemetry, and flush mounted airborne applications. These spirals can be used as a separate component antenna or as broadband feeds for reflector type dish antennas. ALL LX series spiral antennas exhibit an excellent impedance match and radiation pattern control over the broad operating bands in a compact and lightweight package. These spirals are ideally suited for amplitude matching and phase or gain tracking. The unit-to-unit uniformity and frequency independent performance is ideal for airborne monitoring receiving systems.
Designed and Manufactured in England to the highest standards
Disclosed is a coaxial waveguide antenna. In a basic form the coaxial waveguide horn for the antenna comprises an inner section operating in a. Where required for broadband i. The basic structure operates in the linear mode; for polarization diversity and circular polarization, a polarizer is placed in front of the horn, or a dielectric sheet is positioned within a coaxial waveguide section at an angle of This invention pertains to monopulse antennas, and more particularly, to a sum.
New Products
Our OBS series cavity backed spiral antennas are broadband antennas designed for EMC, surveillance, direction finding, telemetry, and flush mounted airborne applications. These spiral antennas can be used as a separate component antenna or as broadband feeds for reflector type dish antennas. All OBS series spiral antennas exhibit an excellent impedance match and radiation pattern control over the broad operating bands in a compact and lightweight package. These spiral antennas are ideally suited for amplitude matching and phase or gain tracking. The unit-to-unit uniformity and frequency independent performance is ideal for airborne monitoring receiving systems. These spiral antennas have been designed to operate in a harsh environment and meet the extremes of the Surroundings Specification. According to customers' requirement, also we provide specific frequency spiral antennas, Especially bandwidth spiral antennas with special demands of frequency.
A Review of 5G Power Amplifier Design at cm-Wave and mm-Wave Frequencies
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