Embedded dielectric rod antenna

Claim 2

An end-fired antenna element for projecting a narrow beam of energy into the surrounding environment, comprising: feed means terminating in an aperature; a dielectric rod of a material having a dielectric constant ε 1 coupled to the aperture and extending longitudinally therefrom; a dielectric material surrounding said dielectric rod along the length thereof having a dielectric constant ε 2 ≧81 and substantially greater than the dielectric constant of the environment but less than the dielectric constant ε 1 .

Claim 3

A directive antenna element, comprising: feed means for delivering a single mode electromagnetic signal; a rod connected to the feed means, constructed of a material having a first dielectric constant; cylindrical material means mounted in the atmosphere and surrounding said rod and constructed of a material having a second dielectric constant ε 2 greater than the dielectric constant of the atmosphere but less than the first dielectric constant and the value of the second dielectric constant being not less than eight-one.

Claim 4

A directive antenna element, comprising: feed means for delivering a single mode electromagnetic signal; a rod connected to the feed means, constructed of a material having a first dielectric constant; cylindrical material means mounted in the atmosphere and surrounding said rod and constructed of a material having a second dielectric constant ε 2 greater than the dielectric constant of the atmosphere but less than the first dielectric constant and the value of the second dielectric constant being not less than eight-one.

Claim 5

An antenna element as set forth in claims 1 or 2 wherein said dielectric rod has an actual length L a and an effective length L e determined by the formula L e =L a √ε 2 .

Claim 6

An end-fired antenna element, comprising: feed means for delivering a single mode electromagnetic signal; a rod of a first material having a dielectric constant, ε 1 , electrically coupled to the feed means; a sheath of a second material having a dielectric constant, ε 2 , greater in value than ten but lesser in value than ε 1 , surrounding the rod; a quarter wave impedance matching transformer coupling the antenna element to the surrounding environment for end fire, said transformer having a dielectric constant equal to the square root of the product of the dielectric constants of the second material and the surrounding environment; wherein the ratio ε 1 /ε 2 ≧3.0.

Claim 7

An end-fired antenna element, comprising: feed means for delivering a single mode electromagnetic signal; a rod of a first material having a dielectric constant, ε 1 , electrically coupled to the feed means; a sheath of a second material having a dielectric constant, ε 2 , greater in value than ten but lesser in value than ε 1 , surrounding the rod; a quarter wave impedance matching transformer coupling the antenna element to the surrounding environment for end fire, said transformer having a dielectric constant equal to the square root of the product of the dielectric constants of the second material and the surrounding environment; wherein the ratio ε 1 /ε 2 ≧3.0.

Claim 8

The antenna set forth in claim 4 wherein ε 2 ≧25.

Claim 9

The antenna set forth in claim 4 wherein ε 2 ≧30.

Claim 10

The antenna set forth in claim 4 wherein ε 2 ≧50.

Claim 11

The antenna set forth in claim 4 wherein ε 2 ≧81.

Claim 12

A polyrod antenna element having a half-power beamwidth θ, in a surrounding environment comprising: feed means terminating in a aperture; a dielectric rod of effective length L extending longitudinally from the feed means and having a dielectric constant ε 1 , wherein the effective length is defined by the equation ##EQU10## a dielectric medium surrounding the rod having a dielectric constant ε 2 less than ε 1 , but substantially greater than the dielectric constant of the surrounding environment, such that: ##EQU11## whereby the actual length L a of the rod is defined by the equation: ##EQU12## a quarter wave impedance matching transformer coupling the antenna element to the surrounding environment for end fire, said transformer having a dielectric constant equal to the square root of the product of the dielectric constants of the dielectric medium and the surrounding environment.

Claim 13

A polyrod antenna element having a half-power beamwidth θ, in a surrounding environment comprising: feed means terminating in a aperture; a dielectric rod of effective length L extending longitudinally from the feed means and having a dielectric constant ε 1 , wherein the effective length is defined by the equation ##EQU10## a dielectric medium surrounding the rod having a dielectric constant ε 2 less than ε 1 , but substantially greater than the dielectric constant of the surrounding environment, such that: ##EQU11## whereby the actual length L a of the rod is defined by the equation: ##EQU12## a quarter wave impedance matching transformer coupling the antenna element to the surrounding environment for end fire, said transformer having a dielectric constant equal to the square root of the product of the dielectric constants of the dielectric medium and the surrounding environment.

Claim 14

A polyrod antenna element having a half-power beamwidth θ in a surrounding environment, comprising: feed means terminating in an aperture; a dielectric rod of effective length L extending longitudinally from the feed means and having a dielectric constant ε 1 , wherein the effective length is defined by the equation ##EQU13## a dielectric medium surrounding the rod having a dielectric constant ε 2 less than ε 1 but substantially greater than the dielectric constar of the surrounding environment, such that: ##EQU14## whereby the actual length L a of the rod is defined by the equation: ##EQU15## a quarter wave impedance matching transformer coupling the antenna element to the surrounding environment for end fire, said transformer having a dielectric constant equal to the square root of the product of the dielectric constants of the dielectric medium and the surrounding environment.

Claim 15

A polyrod antenna element having a half-power beamwidth θ in a surrounding environment, comprising: feed means terminating in an aperture; a dielectric rod of effective length L extending longitudinally from the feed means and having a dielectric constant ε 1 , wherein the effective length is defined by the equation ##EQU13## a dielectric medium surrounding the rod having a dielectric constant ε 2 less than ε 1 but substantially greater than the dielectric constar of the surrounding environment, such that: ##EQU14## whereby the actual length L a of the rod is defined by the equation: ##EQU15## a quarter wave impedance matching transformer coupling the antenna element to the surrounding environment for end fire, said transformer having a dielectric constant equal to the square root of the product of the dielectric constants of the dielectric medium and the surrounding environment.

Claim 16

The antenna element set forth in claims 9 or 10 wherein ε 1 ≧10.

Claim 17

The antenna element set forth in claims 4, 9 or 10 wherein ε 1 ≧25.

Claim 18

In a directive antenna element of the type having in its environment a characteristic three-decibel beamwidth and using a dielectric rod of length L and dielectric constant ε 1 , extending longitudinally from feed means terminating in an aperture, the antenna element comprising: material of dielectric constant ε 2 surrounding the rod wherein the material is selected according to the formula: ##EQU16## where ε 2 is substantially greater than the dielectric constant of the environment and the value of ε 2 ≧81.

Claim 19

In a directive antenna element of the type having in its environment a characteristic three-decibel beamwidth and using a dielectric rod of length L and dielectric constant ε 1 , extending longitudinally from feed means terminating in an aperture, the antenna element comprising: material of dielectric constant ε 2 surrounding the rod wherein the material is selected according to the formula: ##EQU16## where ε 2 is substantially greater than the dielectric constant of the environment and the value of ε 2 ≧81.

Claim 20

The antenna element set forth in claims 1, 2, 4 or 13 further comprising the dielectric materials selected in accordance with the formula: ##EQU17##

Claim 21

The antenna element set forth in claims 1, 2, 4 or 13 further comprising the dielectric material selected in accordance with the formula: ##EQU18##

Claim 22

The antenna set forth in claims 1, 2, 4, 9, 10 or 13 comprising: the dielectric rod having a cross-section normal to its greatest dimension that tapers away from the feed means.

Claim 23

The antenna set forth in claim 16 further comprised of the taper being linear.

Claim 24

The antenna set forth in claim 16 further comprised of the taper being exponential.

Claim 25

The antenna set forth in claim 16 further comprised of the taper being described by the formula: a(z)=1.25=0.60e.sup.-0.62, where a is a cross-sectional dimension and z is a longitudinal dimension.

Claim 26

The antenna set forth in claims 4 or 13 wherein the dielectric material surrounding the dielectric rod separates the dielectric rod from a surrounding environment.

Claim 27

The antenna set forth in claims 1, 9, 10 or 13 wherein the surrounding environment comprises atmosphere.

Claim 28

The antenna set forth in claim 1, 9, 10 or 13 wherein the surrounding environment comprises water.

Claim 29

The antenna set forth in claim 14 wherein the dielectric material surrounding the dielectric rod separates the dielectric rod from a surrounding environment.

Claim 30

The antenna set forth in claim 14 wherein the surrounding environment comprises atmosphere.

Claim 31

The antenna set forth in claim 14 wherein the surrounding environment comprises water.