Direction finding antenna assembly

Claim 2

A direction finding antenna assembly comprising a horn portion including spaced annular reflectors defining an annular outwardly opening space therebetween, said space being shaped to respond to the receipt of signals transmitted from remote locations to establish therein signal mode configurations having characteristics corresponding to the direction from which the signal is received, said modes including a transverse electromagnetic (TEM) mode and a transverse electric (TE10) mode, a pair of spaced concentric tubular members defining an annular chamber therebetween in axial alignment with the annular space between the reflectors, one of which tubular members changes its shape from end to end, means connecting the reflectors to respective ones of the said spaced tubular members to form an annular transition space communicating the space between the reflectors with said annular chamber, said transition space being shaped to convert the aforesaid TEM and TE10 modes existing in the space between the reflectors to TEM and TE11 modes respectively in the annular chamber, four probes extending into the chamber at 90* intervals therearound to define two pairs of opposed probes, said probes responding to the characteristics of the said modes in the annular chamber at the respective probe locations, and means for combining the mode components sensed by the said pairs of opposed probes to produce signals from which the direction of a received signal can be determined, said combining means including a plurality of hybrid circuits and means coupling the said probes to the said hybrid circuits.

Claim 3

A direction finding antenna assembly combining in a single structure a collinear antenna array and a horn antenna structure comprising a horn antenna structure including a pair of spaced axially aligned reflector members shaped to define an annular open sided space capable of receiving and responding to signals transmitted from remote locations by establishing in said space standing microwave signals having configurations that depend on the direction from which a signal is received, said microwave signals being present in said space in a transverse electromagnetic (TEM) mode, and in a transverse electric (TE10) radial-line mode, means including conductive extensions of said spaced reflector members, said extensions defining an annular throat and an annular chamber communicating with the space between said reflectors, said throat being constructed to convert the standing wave TEM and TE10 modes present in the space between the reflectors into TEM and TE11 modes in the chamber, four coupling probes positioned at equispaced locations around the conductive extensions of the reflectors and extending into the annular chamber, said probes being positioned to form two pairs of opposed probes positioned to respond to the characteristics of the said microwave TEM and TE11 modes in the annular chamber at the locations thereof, first and second hybrid circuits each having a pair of input and a pair of output ports, said hybrid circuits being constructed to combine signal components introduced at the input ports thereof, means for coupling the probes of one of said pairs of opposed probes to the input ports of the first hybrid circuit, means for coupling the probes of said other pair of opposed probes to the input ports of the second hybrid circuit, said first and second hybrid circuits combining the inputs received at their respective input ports to produce an output at one of the output ports representing a combination of the in-phase signal components sensed by the said opposed probes and an output at the other output port representing a combination of the out-of-phase signal components, means for mounting said collinear antenna array in the assembly in axial alignment with the horn structure, and means including coaxial feeder connection means for the collinear array, said connection means extending through the horn structure.

Claim 4

A direction finding antenna assembly combining in a single structure a collinear antenna array and a horn antenna structure comprising a horn antenna structure including a pair of spaced axially aligned reflector members shaped to define an annular open sided space capable of receiving and responding to signals transmitted from remote locations by establishing in said space standing microwave signals having configurations that depend on the direction from which a signal is received, said microwave signals being present in said space in a transverse electromagnetic (TEM) mode, and in a transverse electric (TE10) radial-line mode, means including conductive extensions of said spaced reflector members, said extensions defining an annular throat and an annular chamber communicating with the space between said reflectors, said throat being constructed to convert the standing wave TEM and TE10 modes present in the space between the reflectors into TEM and TE11 modes in the chamber, four coupling probes positioned at equispaced locations around the conductive extensions of the reflectors and extending into the annular chamber, said probes being positioned to form two pairs of opposed probes positioned to respond to the characteristics of the said microwave TEM and TE11 modes in the annular chamber at the locations thereof, first and second hybrid circuits each having a pair of input and a pair of output ports, said hybrid circuits being constructed to combine signal components introduced at the input ports thereof, means for coupling the probes of one of said pairs of opposed probes to the input ports of the first hybrid circuit, means for coupling the probes of said other pair of opposed probes to the input ports of the second hybrid circuit, said first and second hybrid circuits combining the inputs received at their respective input ports to produce an output at one of the output ports representing a combination of the in-phase signal components sensed by the said opposed probes and an output at the other output port representing a combination of the out-of-phase signal components, means for mounting said collinear antenna array in the assembly in axial alignment with the horn structure, and means including coaxial feeder connection means for the collinear array, said connection means extending through the horn structure.

Claim 5

The assembly defined in claim 2 including third and fourth hybrid circuits each having a pair of input ports and a pair of output ports, one of said output ports of the third and fourth hybrid circuits having an output thereat representing a combination of the in-phase components of the signals introduced at the input ports and the other output ports of said third and fourth hybrid circuits having outputs thereat representing a combination of the out-of-phase components of the said signals introduced at the input ports, means coupling the respective output ports of the first and second hybrid circuits at which the combination of the in-phase signal components exist to the input ports of the third hybrid circuit, means coupling the respective output ports of the first and second hybrid circuits at which the combination of the out-of-phase signal components exist to the input ports of the fourth hybrid circuit, and means for loading one of the outpuT ports of said third hybrid circuit.

Claim 6

The assembly defined in claim 3 including means for changing the phase of one of the output signals of the second hybrid circuit relative to the corresponding output signals from the first hybrid circuit.

Claim 7

In a direction finding antenna assembly the combination of axially aligned collinear and horn antenna structures one of which is fed by means which extend through the other, the horn structure being defined by spaced annular reflectors constructed to establish TEM and TE10 modes therebetween in response to receipt of signals transmitted by a remote source, means including extensions of the spaced reflectors defining an annular chamber communicating with the space between the reflectors, the construction of said chamber and the communication between the chamber and the space between the reflectors being constructed to convert the TEM and TE10 modes established between the spaced reflectors into corresponding TEM and TE11 modes in the chamber, first an second pairs of coupling probes extending into the chamber at spaced locations therearound to respond to the strengths of the signal modes thereat, first and second hybrid circuits each having a pair of input and a pair of output ports, means coupling the probes of one of said pairs respectively to the input ports of said first hybrid circuit, means coupling the probes of said other pair of probes respectively to the input ports of said second hybrid circuit, each of said hybrid circuits being constructed to combine the signals it receives at its input ports including means for combining the signals to produce an output at one of its output ports which represents the combined in-phase components of the input signals and an output at its other output port which represents the combined out-of-phase components of the input signals, a third hybrid circuit having a pair of input and a pair of output ports, means coupling the output ports of said first and second hybrid circuits where the combined in-phase components exist to respective input ports of said third hybrid circuit, a fourth hybrid circuit having a pair of input and a pair of output ports, means coupling the outputs of said first and second hybrid circuits where the combined out-of-phase components exist to the respective input ports of said fourth hybrid circuit, said last named coupling means including means for changing the phase of the output at one of the output ports of said second hybrid circuit by approximately 90* relative to the output at the corresponding output port of said first hybrid circuit.

Claim 8

In a direction finding antenna assembly the combination of axially aligned collinear and horn antenna structures one of which is fed by means which extend through the other, the horn structure being defined by spaced annular reflectors constructed to establish TEM and TE10 modes therebetween in response to receipt of signals transmitted by a remote source, means including extensions of the spaced reflectors defining an annular chamber communicating with the space between the reflectors, the construction of said chamber and the communication between the chamber and the space between the reflectors being constructed to convert the TEM and TE10 modes established between the spaced reflectors into corresponding TEM and TE11 modes in the chamber, first an second pairs of coupling probes extending into the chamber at spaced locations therearound to respond to the strengths of the signal modes thereat, first and second hybrid circuits each having a pair of input and a pair of output ports, means coupling the probes of one of said pairs respectively to the input ports of said first hybrid circuit, means coupling the probes of said other pair of probes respectively to the input ports of said second hybrid circuit, each of said hybrid circuits being constructed to combine the signals it receives at its input ports including means for combining the signals to produce an output at one of its output ports which represents the combined in-phase components of the input signals and an output at its other output port which represents the combined out-of-phase components of the input signals, a third hybrid circuit having a pair of input and a pair of output ports, means coupling the output ports of said first and second hybrid circuits where the combined in-phase components exist to respective input ports of said third hybrid circuit, a fourth hybrid circuit having a pair of input and a pair of output ports, means coupling the outputs of said first and second hybrid circuits where the combined out-of-phase components exist to the respective input ports of said fourth hybrid circuit, said last named coupling means including means for changing the phase of the output at one of the output ports of said second hybrid circuit by approximately 90* relative to the output at the corresponding output port of said first hybrid circuit.

Claim 9

The direction finding antenna defined in claim 5 wherein said means for changing the phase of the output of one of the output ports of said second hybrid circuit relative to the output at the corresponding output port of said first hybrid circuit includes means forming a longer coupling path between the said one output port and the input port at the fourth hybrid circuit to which it is coupled relative to the length of the coupling means between the corresponding output port of said first hybrid circuit and the other input port at the said fourth hybrid circuit.

Claim 10

The direction finding antenna defined in claim 5 including means for tuning at least one of the said hybrid circuits.

Claim 11

The direction finding antenna defined in claim 5 including means for predeterminately loading at least one output port of said third hybrid circuit.

Claim 12

A direction finding antenna assembly comprising a horn portion including spaced annular reflectors defining an annular outwardly opening spaced therebetween, said space being shaped to respond to the receipt of signals transmitted from remote locations to establish therein signal mode configurations having characteristics corresponding to the direction from which the signal is received, said modes including a transverse electromagnetic (TEM) mode and a transverse electric (TE10) mode, a pair of spaced concentric tubUlar members defining an annular chamber therebetween in axial alignment with the annular space between the reflectors, means connecting the reflectors to respective ones of the said spaced tubular members to form an annular transition space communicating the space between the reflectors with said annular chamber, said transition space being shaped to convert the aforesaid TEM and TE10 modes existing in the space between the reflectors to TEM and TE11 modes respectively in the annular chamber, four probes extending into the chamber at 90* intervals therearound to define two pairs of opposed probes, said probes responding to the characteristics of the said modes in the annular chamber at the respective probe locations, means for combining the mode components sensed by the said pairs of opposed probes to produce signals from which the direction of a received signal can be determined, said combining means including a plurality of hybrid circuits and means coupling the said probes to the said hybrid circuits, a collinear antenna array including means for mounting said array on the horn portion in axial alignment therewith, and means coupling said array to a source of radiation energy, said coupling means including coaxial coupling means extending through the horn portion.

Claim 13

A direction finding antenna assembly comprising a horn portion including spaced annular reflectors defining an annular outwardly opening spaced therebetween, said space being shaped to respond to the receipt of signals transmitted from remote locations to establish therein signal mode configurations having characteristics corresponding to the direction from which the signal is received, said modes including a transverse electromagnetic (TEM) mode and a transverse electric (TE10) mode, a pair of spaced concentric tubUlar members defining an annular chamber therebetween in axial alignment with the annular space between the reflectors, means connecting the reflectors to respective ones of the said spaced tubular members to form an annular transition space communicating the space between the reflectors with said annular chamber, said transition space being shaped to convert the aforesaid TEM and TE10 modes existing in the space between the reflectors to TEM and TE11 modes respectively in the annular chamber, four probes extending into the chamber at 90* intervals therearound to define two pairs of opposed probes, said probes responding to the characteristics of the said modes in the annular chamber at the respective probe locations, means for combining the mode components sensed by the said pairs of opposed probes to produce signals from which the direction of a received signal can be determined, said combining means including a plurality of hybrid circuits and means coupling the said probes to the said hybrid circuits, a collinear antenna array including means for mounting said array on the horn portion in axial alignment therewith, and means coupling said array to a source of radiation energy, said coupling means including coaxial coupling means extending through the horn portion.

Claim 14

A direction finding antenna assembly comprising a horn portion including spaced annular reflectors defining an annular outwardly opening space therebetween, said space being shaped to respond to the receipt of signals transmitted from remote locations to establish therein signal mode configurations having characteristics corresponding to the direction from which the signal is received, said modes including a transverse electromagnetic (TEM) mode and a transverse electric (TE10) mode, a pair of spaced concentric tubular members defining an annular chamber therebetween in axial alignment with the annular space between the reflectors, means connecting the reflectors to respective ones of the said spaced tubular members to form an annular transition space communicating the space between the reflectors with said annular chamber, said transition space being shaped to convert the aforesaid TEM and TE10 modes existing in the space between the reflectors to TEM and TE11 modes respectively in the annular chamber, four probes extending into the chamber at 90* intervals therearound to define two pairs of opposed probes, said probes responding the the characteristics of the said modes in the annular chamber at the respective probe locations, means for combining the mode components sensed by the said pairs of opposed probes to produce signals from which the direction of a received signal can be determined, said combining means including a plurality of hybrid circuits and means coupling the said probes to the said hybrid circuits, and means forming a space of predetermined dimensions immediately above and immediately below the reflectors in the horn portion, said spaces being constructed to produce a choke effect to minimize undesirable currents and to reduce the elevation of side lobe radiations.

Claim 15

A direction finding antenna assembly comprising a horn portion including spaced annular reflectors defining an annular outwardly opening space therebetween, said space being shaped to respond to the receipt of signals transmitted from remote locations to establish therein signal mode configurations having characteristics corresponding to the direction from which the signal is received, said modes including a transverse electromagnetic (TEM) mode and a transverse electric (TE10) mode, a pair of spaced concentric tubular members defining an annular chamber therebetween in axial alignment with the annular space between the reflectors, means connecting the reflectors to respective ones of the said spaced tubular members to form an annular transition space communicating the space between the reflectors with said annular chamber, said transition space being shaped to convert the aforesaid TEM and TE10 modes existing in the space between the reflectors to TEM and TE11 modes respectively in the annular chamber, four probes extending into the chamber at 90* intervals therearound to define two pairs of opposed probes, said probes responding the the characteristics of the said modes in the annular chamber at the respective probe locations, means for combining the mode components sensed by the said pairs of opposed probes to produce signals from which the direction of a received signal can be determined, said combining means including a plurality of hybrid circuits and means coupling the said probes to the said hybrid circuits, and means forming a space of predetermined dimensions immediately above and immediately below the reflectors in the horn portion, said spaces being constructed to produce a choke effect to minimize undesirable currents and to reduce the elevation of side lobe radiations.