Microwave transition using dielectric waveguides

A microwave transition comprising

• a single-moded metal waveguide adapted to operate at a wavelength .lambda..sub.0,
• a dielectric rod mounted coaxially within the distal end portion of said metal waveguide and made of a first dielectric material having a dielectric constant .epsilon..sub.1, a distal portion of said dielectric rod extending beyond the distal end of said metal waveguide,
• a second dielectric material surrounding and extending beyond said dielectric rod beyond the distal end of said metal waveguide and having a dielectric constant .epsilon..sub.2 lower than the dielectric constant of said first dielectric material, an end portion of said dielectric rod tapering inwardly toward the distal end thereof defining a dielectric transition region for launching signals propagating toward the distal end of said dielectric rod into said second dielectric material, said signals being single-moded throughout said dielectric transition region, said dielectric rod having a diameter d.sub.1 at the beginning of said dielectric transition region and terminating within said second dielectric material defining an end of said dielectric transition region, said signals propagating beyond said dielectric rod and through said second dielectric material at the end of said dielectric transition region, said second dielectric material having a diameter d.sub.2 at the end of said dielectric transition region, and
• a third dielectric material surrounding said second dielectric material and having a dielectric constant .epsilon..sub.3 lower than the dielectric constant of said second dielectric material,
• said first dielectric material having a wavenumber V.sub.1 defined by the equation .pi.d.sub.1 (.lambda..sub.0).sup.-1 (.epsilon..sub.1 -.epsilon..sub.2).sup.1/2, said second dielectric material having a wavenumber V.sub.2 defined by the equation .pi.d.sub.2 (.lambda..sub.0).sup.-1 (.epsilon..sub.2 -.epsilon..sub.3).sup.1/2, said wavenumbers V.sub.1 and V.sub.2 having values between an upper limit and a lower limit, said upper limit defining a point at which the first and second dielectric materials are capable of supporting other than fundamental waveguide modes, said lower limit defining a point at which pattern degradation occurs due to fields extending too far outside of said first and second dielectric materials.

A microwave antenna comprising

• a single moded metal waveguide adapted to operate at a wavelength .lambda..sub.0, said metal waveguide tapering inwardly to a cutoff dimension near the distal end thereof, said cutoff dimension selected to enable propagation of a fundamental waveguide mode while cutting off higher order modes,
• a first dielectric waveguide having a dielectric constant .epsilon..sub.1 mounted coaxially within the distal end portion of said metal waveguide, a distal portion of said first dielectric waveguide extending beyond the distal end of said metal waveguide, and
• a second dielectric waveguide surrounding and extending beyond said first dielectric waveguide beyond the distal end of said metal waveguide and having a dielectric constant .epsilon..sub.2 lower than the dielectric constant of said first dielectric waveguide, an end portion of said first dielectric waveguide tapering inwardly toward the axis thereof defining a dielectric transition region for launching signals propagating toward the distal end of said first dielectric waveguide into said second dielectric waveguide, said signals being single-moded throughout said dielectric transition region, said first dielectric waveguide having a diameter d.sub.1 at the beginning of said dielectric transition region and terminating within said second dielectric waveguide defining an end of said dielectric transition region, said signals propagating beyond said first dielectric waveguide and through said second dielectric waveguide at the end of said dielectric transition region, said second dielectric waveguide having a diameter d.sub.2 at the end of said dielectric transition region, said first dielectric waveguide having a wavenumber V.sub.1 defined by the equation .pi.d.sub.1 (.lambda..sub.0).sup.-1 (.epsilon..sub.1 -.epsilon..sub.2).sup.1/2, said second dielectric waveguide having a wavenumber V.sub.2 defined by the equation .pi.d.sub.2 (.lambda..sub.0).sup.-1 (.epsilon..sub.2 -1).sup.1/2, said wavenumbers V.sub.1 and V.sub.2 having values between an upper limit and a lower limit, said upper limit defining a point at which the first and second dielectric materials are capable of supporting other than fundamental waveguide modes, said lower limit defining a point at which pattern degradation occurs due to fields extending too far outside of said first and second dielectric materials.

A microwave transition comprising

• a single-moded metal waveguide adapted to operate at a wavelength .lambda..sub.0,
• a dielectric rod mounted coaxially within the distal end portion of said metal waveguide and made of a first dielectric material having a dielectric constant .epsilon..sub.1, a distal end portion of said dielectric rod extending beyond the distal end of said metal waveguide, and
• a second dielectric material surrounding said dielectric rod beyond the distal end of said metal waveguide and having a dielectric constant .epsilon..sub.2 lower than the dielectric constant of said first dielectric material, an end portion of said dielectric rod tapering inwardly toward the distal end thereof defining a dielectric transition region for launching signals propagating toward the distal end of said dielectric rod into said second dielectric material. said dielectric rod having a diameter d.sub.1 at the beginning of said dielectric transition region, said second dielectric material having a substantially constant diameter throughout said dielectric transition region, said second dielectric material having a diameter d.sub.2 at the end of said dielectric transition region, said first dielectric material having a wavenumber V.sub.1 defined by the equation .pi.d.sub.1 (.lambda..sub.0).sup.-1 (.epsilon..sub.1 -.epsilon..sub.2).sup.1/2, said second dielectric material having a wavenumber V.sub.2 defined by the equation .pi.d.sub.2 (.lambda..sub.0).sup.-1 (.epsilon..sub.2 =1).sup.1/2, said wavenumbers V.sub.1 and V.sub.2 having values between an upper limit and a lower limit, said upper limit defining a point at which the first and second dielectric materials are capable of supporting other than fundamental waveguide modes, said lower limit defining a point at which pattern degradation occurs due to fields extending too far outside of said first and second dielectric materials.

A microwave antenna comprising

• a single moded metal waveguide adapted to operate at a wavelength .lambda..sub.0, said metal waveguide tapering inwardly to a cutoff dimension near the distal end thereof, said cutoff dimension selected to enable propagation of a fundamental waveguide mode while cutting off higher order modes,
• a first dielectric waveguide having a dielectric constant .epsilon..sub.1 mounted coaxially within the distal end portion of said metal waveguide, a distal portion of said first dielectric waveguide extending beyond the distal end of said metal waveguide, and
• a second dielectric waveguide surrounding said first dielectric waveguide beyond the distal end of said metal waveguide and having a dielectric constant .epsilon..sub.2 lower than the dielectric constant of said first dielectric waveguide, an end portion of said first dielectric waveguide tapering inwardly toward the axis thereof defining a dielectric transition region for launching signals propagating toward the distal end of said first dielectric waveguide into said second dielectric waveguide, said first dielectric waveguide having a diameter d.sub.1 at the beginning of said dielectric transition region, said second dielectric waveguide having a substantially constant diameter throughout said dielectric transition region, said second dielectric waveguide having a diameter d.sub.2 at the end of said dielectric transition region, said first dielectric waveguide having a wavenumber V.sub.1 defined by the equation .pi.d.sub.1 (.lambda..sub.0).sup.-1 (.epsilon..sub.1 -.epsilon..sub.2).sup.1/2, said second dielectric waveguide having a wavenumber V.sub.2 defined by the equation .pi.d.sub.2 (.lambda..sub.0).sup.-1 (.epsilon..sub.2 -1).sup.1/2, said wavenumbers V.sub.1 and V.sub.2 having values between an upper limit and a lower limit, said upper limit defining a point at which the first and second dielectric materials are capable of supporting other than fundamental waveguide modes, said lower limit defining a point at which pattern degradation occurs due to fields extending too far outside of said first and second dielectric materials.

A microwave transition comprising

• a single-moded metal waveguide adapted to operate at a wavelength .lambda..sub.0,
• a dielectric rod mounted coaxially within the distal end portion of said metal waveguide and made of a first dielectric material having a dielectric constant .epsilon..sub.1, a distal end portion of said dielectric rod extending beyond the distal end of said metal waveguide, and
• a second dielectric material surrounding said dielectric rod beyond the distal end of said metal waveguide and having a dielectric constant .epsilon..sub.2 lower than the dielectric constant of said first dielectric material, an end portion of said dielectric rod tapering inwardly toward the distal end thereof defining a dielectric transition region for launching signals propagating toward the distal end of said dielectric rod into said second dielectric material, said dielectric rod having a diameter d.sub.1 at the beginning of said dielectric transition region, said second dielectric material having a diameter d.sub.2 at the end of said dielectric transition region, said first dielectric material having a wavenumber V.sub.2 defined by the equation .pi.d.sub.1 (.lambda..sub.0).sup.-1 (.epsilon..sub.1 -.epsilon..sub.2).sup.1/2, said second dielectric material having a wavenumber V.sub.2 defined by the equation .pi.d.sub.2 (.lambda..sub.0).sup.-1 (.epsilon..sub.2 -1).sup.1/2, said wavenumbers V.sub.1 and V.sub.2 having values between an upper limit and a lower limit, said upper limit defining a point at which the first and second dielectric materials are capable of supporting other than fundamental waveguide modes, the upper limit of the wavenumbers V.sub.1 and V.sub.2 being about 2.4, said lower limit defining a point at which pattern degradation occurs due to fields extending too far outside of said first and second dielectric materials.

A microwave transition comprising

• a single-moded metal waveguide adapted to operate at a wavelength .lambda..sub.0,
• a dielectric rod mounted coaxially within the distal end portion of said metal waveguide and made of a first dielectric material having a dielectric constant .epsilon..sub.1, a distal end portion of said dielectric rod extending beyond the distal end of said metal waveguide, and
• a second dielectric material surrounding said dielectric rod beyond the distal end of said metal waveguide and having a dielectric constant .epsilon..sub.2 lower than the dielectric constant of said first dielectric material, an end portion of said dielectric rod tapering inwardly toward the distal end thereof defining a dielectric transition region for launching signals propagating toward the distal end of said dielectric rod into said second dielectric material, said dielectric rod having a diameter d.sub.1 at the beginning of said dielectric transition region, said second dielectric material having a diameter d.sub.2 at the end of said dielectric transition region, said first dielectric material having a wavenumber V.sub.1 defined by the equation .pi.d.sub.1 (.lambda..sub.0).sup.-1 (.epsilon..sub.1 -.epsilon..sub.2).sup.1/2, said second dielectric material having a wavenumber V.sub.2 defined by the equation .pi.d.sub.2 (.lambda..sub.0).sup.-1 (.epsilon..sub.2 -1).sup.1/2, said wavenumbers V.sub.1 and V.sub.2 having values between an upper limit and a lower limit, said upper limit defining a point at which the first and second dielectric materials are capable of supporting other than fundamental waveguide modes, said lower limit defining a point at which pattern degradation occurs due to fields extending too far outside of said first and second dielectric materials, the lower limit of the wavenumber V.sub.1 being about 1.5 and the lower limit of the wavenumber V.sub.2 being about 1.0.

A microwave transition comprising

• a single-moded metal waveguide adapted to operate at a wavelength .lambda..sub.0,
• a dielectric rod mounted coaxially within the distal end portion of said metal waveguide and made of a first dielectric material having a dielectric constant .epsilon..sub.1, a distal portion of said dielectric rod extending beyond the distal end of said metal waveguide,
• a second dielectric material surrounding said dielectric rod beyond the distal end of said metal waveguide and having a dielectric constant .epsilon..sub.2 lower than the dielectric constant of said first dielectric material, an end portion of the dielectric rod tapering inwardly at an angle of less than about five degrees toward the distal end thereof defining a dielectric transition region for launching signals propagating toward the distal end of said dielectric rod into said second dielectric material, said dielectric rod having a diameter d.sub.1 at the beginning of said dielectric transition region, said second dielectric material having a diameter d.sub.2 at the end of said dielectric transition region, and
• a third dielectric material surrounding said second dielectric material and having a dielectric constant .epsilon..sub.3 lower than the dielectric constant of said second dielectric material,
• said first dielectric material having a wavenumber V.sub.1 defined by the equation .pi.d.sub.1 (.lambda..sub.0).sup.-1 (.epsilon..sub.1 -.epsilon..sub.2).sup.1/2, said second dielectric material having a wavenumber V.sub.2 defined by the equation .pi.d.sub.2 (.lambda..sub.0).sup.-1 (.epsilon..sub.2 -.epsilon..sub.3).sup.1/2, said wavenumbers V.sub.1 and V.sub.2 having values between an upper limit and a lower limit, said upper limit defining a point at which the first and second dielectric materials are capable of supporting other than fundamental waveguide modes, said lower limit defining a point at which pattern degradation occurs due to fields extending too far outside of said first and second dielectric materials.

A microwave transition comprising

• a single-moded metal waveguide adapted to operate at a wavelength .lambda..sub.0,
• a dielectric rod mounted coaxially within the distal end portion of said metal waveguide and made of a first dielectric material having a dielectric constant .epsilon..sub.1, a distal portion of said dielectric rod extending beyond the distal end of said metal waveguide,
• a second dielectric material surrounding said dielectric rod beyond the distal end of said metal waveguide and having a dielectric constant .epsilon..sub.2 lower than the dielectric constant of said first dielectric material, an end portion of the dielectric rod tapering inwardly toward the distal end thereof defining a dielectric transition region for launching signals propagating toward the distal end of said dielectric rod into said second dielectric material, said dielectric rod having a diameter d.sub.1 at the beginning of said dielectric transition region, said second dielectric material having a constant diameter throughout said dielectric transition region, said second dielectric material having a diameter d.sub.2 at the end of said dielectric transition region;
• and
• a third dielectric material surrounding said second dielectric material and having a dielectric constant .epsilon..sub.3 lower than the dielectric constant of said second dielectric material,
• said first dielectric material having a wavenumber V.sub.1 defined by the equation .pi.d.sub.1 (.lambda..sub.0).sup.-1 (.epsilon..sub.1 -.epsilon..sub.2).sup.1/2,said second dielectric material having a wavenumber V.sub.2 defined by the equation .pi.d.sub.2 (.lambda..sub.0).sup.-1 (.epsilon..sub.2 -.epsilon..sub.3).sup.1/2, said wavenumbers V.sub.1 and V.sub.2 having values between an upper limit and a lower limit, said upper limit defining a point at which the first and second dielectric materials are capable of supporting other than fundamental waveguide modes, said lower limit defining a point at which pattern degradation occurs due to fields extending too far outside of said first and second dielectric materials.

A microwave transition comprising

• a single-moded metal waveguide adapted to operate at a wavelength .lambda..sub.0,
• a dielectric rod mounted coaxially within the distal end portion of said metal waveguide and made of a first dielectric material having a dielectric constant .epsilon..sub.1, a distal portion of said dielectric rod extending beyond the distal end of said metal waveguide,
• a second dielectric material surrounding said dielectric rod beyond the distal end of said metal waveguide and having a dielectric constant .epsilon..sub.2 lower than the dielectric constant of said first dielectric material, an end portion of the dielectric rod tapering inwardly toward the distal end thereof defining a dielectric transition region for launching signals propagating toward the distal end of said dielectric rod into said second dielectric material, said dielectric rod having a diameter d.sub.1 at the beginning of said dielectric transition region, said second dielectric material having a diameter d.sub.2 at the end of said dielectric transition region, and
• a third dielectric material surrounding said second dielectric material and having a dielectric constant .epsilon..sub.3 lower than the dielectric constant of said second dielectric material,
• said first dielectric material having a wavenumber V.sub.1 defined by the equation .pi.d.sub.1 (.lambda..sub.0).sup.-1 (.epsilon..sub.1 -.epsilon..sub.2).sup.1/2, said second dielectric material having a wavenumber V.sub.2 defined by the equation .pi.d.sub.2 (.lambda..sub.0).sup.-1 (.epsilon..sub.2 -.epsilon..sub.3).sup.1/2, said wavenumbers V.sub.1 and V.sub.2 having values between an upper limit and a lower limit, said upper limit defining a point at which the first and second dielectric materials are capable of supporting other than fundamental waveguide modes, the upper limit of the wavenumbers V.sub.1 and V.sub.2 being about 2.4, said lower limit defining a point at which pattern degradation occurs due to fields extending too far outside of said first and second dielectric materials.

A microwave transition comprising

• a single-moded metal waveguide adapted to operate at a wavelength .lambda..sub.0,
• a dielectric rod mounted coaxially within the distal end portion of said metal waveguide and made of a first dielectric material having a dielectric constant .epsilon..sub.1, a distal portion of said dielectric rod extending beyond the distal end of said metal waveguide,
• a second dielectric material surrounding said dielectric rod beyond the distal end of said metal waveguide and having a dielectric constant .epsilon..sub.2 lower than the dielectric constant of said first dielectric material, an end portion of the dielectric rod tapering inwardly toward the distal end thereof defining a dielectric transition region for launching signals propagating toward the distal end of said dielectric rod into said second dielectric material, said dielectric rod having a diameter d.sub.1 at the beginning of said dielectric transition region, said second dielectric material having a diameter d.sub.2 at the end of said dielectric transition region, and
• a third dielectric material surrounding said second dielectric material and having a dielectric constant .epsilon..sub.3 lower than the dielectric constant of said second dielectric material,
• said first dielectric material having a wavenumber V.sub.1 defined by the equation .pi.d.sub.1 (.lambda..sub.0).sup.-1 (.epsilon..sub.1 -.epsilon..sub.2).sup.1/2, said second dielectric material having a wavenumber V.sub.2 defined by the equation .pi.d.sub.1 (.lambda..sub.0).sup.-1 (.epsilon..sub.2 -.epsilon..sub.3).sup.1/2, said wavenumbers V.sub.1 and V.sub.2 having values between an upper limit and a lower limit, said upper limit defining a point at which the first and second dielectric materials are capable of supporting other than fundamental waveguide modes, said lower limit defining a point at which pattern degradation occurs due to fields extending too far outside of said first and second dielectric materials, the lower limit of the wavenumber V.sub.1 being about 1.5 and the lower limit of the wavenumber V.sub.2 being about 1.0.

A microwave transition comprising

• a single-moded metal waveguide adapted to operate at a wavelength .lambda..sub.0,
• a dielectric rod mounted coaxially within the distal end portion of said metal waveguide and made of a first dielectric material having a dielectric constant .epsilon..sub.1, a distal portion of said dielectric rod extending beyond the distal end of said metal waveguide,
• a second dielectric material surrounding said dielectric rod beyond the distal end of said metal waveguide and having a dielectric constant .epsilon..sub.2 lower than the dielectric constant of said first dielectric material, an end portion of the dielectric rod tapering inwardly toward the distal end thereof defining a dielectric transition region for launching signals propagating toward the distal end of said dielectric rod into said second dielectric material, said dielectric rod having a diameter d.sub.1 at the beginning of said dielectric transition region, said second dielectric material having a diameter d.sub.2 at the end of said dielectric transition region, the second dielectric material tapering inwardly toward the distal end thereof to increase the gain of the antenna, and
• a third dielectric material surrounding said second dielectric material and having a dielectric constant .epsilon..sub.3 lower than the dielectric constant of said second dielectric material,
• said first dielectric material having a wavenumber V.sub.1 defined by the equation .pi.d.sub.1 (.lambda..sub.0).sup.-1 (.epsilon..sub.1 -.epsilon..sub.2).sup.1/2, said second dielectric material having a wavenumber V.sub.2 defined by the equation .pi.d.sub.1 (.lambda..sub.0).sup.-1 (.epsilon..sub.2 -.epsilon..sub.3).sup.1/2, said wavenumbers V.sub.1 and V.sub.2 having values between an upper limit and a lower limit, said upper limit defining a point at which the first and second dielectric materials are capable of supporting other than fundamental waveguide modes, said lower limit defining a point at which pattern degradation occurs due to fields extending too far outside of said first and second dielectric materials.

A microwave antenna comprising

• a single moded metal waveguide adapted to operate at a wavelength .lambda..sub.0, said metal waveguide tapering inwardly to a cutoff dimension near the distal end thereof, said cutoff dimension selected to enable propagation of a fundamental waveguide mode while cutting off higher order modes,
• a first dielectric waveguide having a dielectric constant .epsilon..sub.1 mounted coaxially within the distal end portion of said metal waveguide, a distal portion of said first dielectric waveguide extending beyond the distal end of said metal waveguide, and
• a second dielectric waveguide surrounding said first dielectric waveguide beyond the distal end of said metal waveguide and having a dielectric constant .epsilon..sub.2 lower than the dielectric constant of said first dielectric waveguide, an end portion of said first dielectric waveguide tapering inwardly toward the axis thereof defining a dielectric transition region for launching signals propagating toward the distal end of said first dielectric waveguide into said second dielectric waveguide, said first dielectric waveguide having a diameter d.sub.1 at the beginning of said dielectric transition region, said second dielectric waveguide having a diameter d.sub.2 at the end of said dielectric transition region, said first dielectric waveguide having a wavenumber V.sub.1 defined by the equation .pi.d.sub.1 (.lambda..sub.0).sup.-1 (.epsilon..sub.1 -.epsilon..sub.2).sup.1/2, said second dielectric waveguide having a wavenumber V.sub.2 defined by the equation .pi.d.sub.2 (.lambda..sub.0).sup.-1 (.epsilon..sub.2 -1).sup.1/2, said wavenumbers V.sub.1 and V.sub.2 having values between an upper limit and a lower limit, said upper limit defining a point at which the first and second dielectric materials are capable of supporting other than fundamental waveguide modes, the upper limit of the wavenumbers V.sub.1 and V.sub.2 being about 2.4, said lower limit defining a point at which pattern degradation occurs due to fields extending too far outside of said first and second dielectric materials.

A microwave antenna comprising

• a single moded metal waveguide adapted to operate at a wavelength .lambda..sub.0, said metal waveguide tapering inwardly to a cutoff dimension near the distal end thereof, said cutoff dimension selected to enable propagation of a fundamental waveguide mode while cutting off higher order modes,
• a first dielectric waveguide having a dielectric constant .epsilon..sub.1 mounted coaxially within the distal end portion of said metal waveguide, a distal portion of said first dielectric waveguide extending beyond the distal end of said metal waveguide, and
• a second dielectric waveguide surrounding said first dielectric waveguide beyond the distal end of said metal waveguide and having a dielectric constant .epsilon..sub.2 lower than the dielectric constant of said first dielectric waveguide, an end portion of said first dielectric waveguide tapering inwardly toward the axis thereof defining a dielectric transition region for launching signals propagating toward the distal end of said first dielectric waveguide into said second dielectric waveguide, said first dielectric waveguide having a diameter d.sub.1 at the beginning of said dielectric transition region, said second dielectric waveguide having a diameter d.sub.2 at the end of said dielectric transition region, said first dielectric waveguide having a wavenumber V.sub.1 defined by the equation .pi.d.sub.1 (.lambda..sub.0).sup.-1 (.epsilon..sub.1 -.epsilon..sub.2).sup.1/2, said second dielectric waveguide having a wavenumber V.sub.2 defined by the equation .pi.d.sub.2 (.lambda..sub.0).sup.-1 (.epsilon..sub.2 -1).sup.1/2, said wavenumbers V.sub.1 and V.sub.2 having values between an upper limit and a lower limit, said upper limit defining a point at which the first and second dielectric materials are capable of supporting other than fundamental waveguide modes, said lower limit defining a point at which pattern degradation occurs due to fields extending too far outside of said first and second dielectric materials, the lower limit of the wavenumber V.sub.1 being about 1.5 and the lower limit of the wavenumber V.sub.2 being about 1.0.