Low visibility dual band antenna with dual polarization
First Claim
1. A low-visibility, field-diverse dual band monopole antenna for providing communications comprising:
- an antenna-supporting core comprising printed circuit board (PCB) substrate and having a width and a length; and
an antenna, said antenna wrapped upon said core in a manner for two selected dual band resonant frequencies, said antenna radiating in a diverse manner with horizontal and vertical field components of a field radiated by said antenna substantially in phase and not circularly polarized;
whereby the low-visibility, field-diverse dual band antenna is realized having helical antenna characteristics without severe circular polarization radiation thereby promoting reliable communications.
8 Assignments
0 Petitions
Accused Products
Abstract
A low visibility, field-diverse, dual band antenna provides cross-polarized fields enhancing signal communications. A generally flat, but helical, antenna is achieved in conjunction with a core substrate about which the antenna is wrapped, wound, or fixed. The core substrate, pitch or angle of the helix, and length of the transmitting antenna are chosen for a specific two (2) selected resonant frequency. A two-pole low-pass filter may be used to achieve dual band transmission. The passive components are specifically selected to achieve two (2) resonant frequencies PCS/Cellular 821-896 MHz and 1850-1990 MHz. The length and width of the helix are chosen in order to dimension the helical antenna between its linear and circular polarization modes to thereby deliver field-diverse and cross-polarized transmission modes.
57 Citations
45 Claims
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1. A low-visibility, field-diverse dual band monopole antenna for providing communications comprising:
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an antenna-supporting core comprising printed circuit board (PCB) substrate and having a width and a length; and
an antenna, said antenna wrapped upon said core in a manner for two selected dual band resonant frequencies, said antenna radiating in a diverse manner with horizontal and vertical field components of a field radiated by said antenna substantially in phase and not circularly polarized;
wherebythe low-visibility, field-diverse dual band antenna is realized having helical antenna characteristics without severe circular polarization radiation thereby promoting reliable communications. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
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26. A low-visibility, field-diverse antenna for providing communications, comprising:
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a generally thin and approximately square antenna-supporting core comprising printed circuit board (PCB) substrate having a width and a length, said core conducting from one flat side to another via at least a portion of a plated-through hole in said core;
an antenna, said antenna comprising conducting foil fixed upon said core in a manner for two selected dual band resonant PCS/Cellular frequencies at 821-896 MHz and 1850-1990 MHz, said antenna radiating in a diverse manner with horizontal and vertical field components of a field radiated by said antenna are substantially in phase and not circularly polarized;
said antenna having a two-pole low-pass filter that enables operation at said two selected resonant frequencies, including a first capacitor shunted to ground and in parallel to an input to the antenna, an adjustable inductor coupled to said first capacitor and in series with said input, and a second capacitor coupled to said adjustable inductor on a side of said adjustable inductor opposite that of said input, said second capacitor shunted to ground and in parallel to said first capacitor such that said two selected resonant frequencies are enabled for transmission by the antenna;
said first capacitor being an approximately 1 pf at 1 kV ceramic capacitor, said adjustable inductor being a manually-adjustable brass ribbon or sheet, and said second capacitor being an approximately 1.5 pf at 1 kV ceramic capacitor; and
said antenna terminating in an extended area of conductor having a width generally greater than that of said conducting foil, said extended area covering an end of said antenna-supporting core;
wherebythe low-visibility, field-diverse dual band antenna is realized having helical antenna characteristics without severe circular polarization radiation thereby promoting reliable communications. - View Dependent Claims (27)
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28. A method for constructing a low-visibility, field-diverse dual band monopole antenna, the steps comprising:
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providing an antenna-supporting core;
providing a conductor;
fixing said conductor upon said core;
attaching said conductor to said core in a manner whereby a length of said conductor is engaged by said core in a manner for two selected dual band resonant frequencies, said conductor radiating in a diverse manner with horizontal and vertical field components of a field radiated by said conductor substantially in phase and not circularly polarized;
wherebythe low-visibility, field-diverse dual band antenna is realized having helical antenna characteristics without severe circular polarization radiation thereby promoting reliable communications. - View Dependent Claims (29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45)
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Specification