Differential time delay shifter apparatus and method

Abstract

To provide a highly reliable differential time delay shifter. [Solution] The differential time delay shifter may include a 1-to-N switch (N is an integer greater than 1), which may have a pole contact, N throw contacts, and a pole arm for selectively coupling the pole contact to one of the throw contacts. One throw contact may be the first throw contact in a first switch position and the last throw contact in a last switch position. The shifter may further include one or more transmission lines, each electrically connected between two of the N throw contacts, and may further include a source configured to generate an electromagnetic signal. The source may be electrically coupled to the pole contacts to transmit the signal to the pole contacts. The shifter may further include one or more loads, one of which is electrically coupled to the first throw contact.

Description

Related Applications

[0001] This application claims the benefit of U.S. Provisional Application No. 62 / 949,152, filed December 17, 2019, the entire teachings of which are incorporated herein by reference. [Background technology]

[0002] In cellular communication systems, interference between base stations of adjacent cells must be minimized to facilitate frequency reuse between cells. Controlling the radiation pattern of base station transmitters is one way to reduce such inter-cell interference. For example, one way to reduce interference between cell sites is to tilt the antenna's vertical (elevation) pattern downward toward the ground, thereby reducing the cell site's coverage area. This can be achieved by mechanically tilting the antenna downward using an adjustable bracket, but this tilt can alternatively be achieved by steering the transmit beam downward using a phased array antenna configuration.

[0003] Phased array antennas can be used to directionally steer beams of electromagnetic (EM) radiation. A prior art example of a phased array antenna system is shown in FIG. 1. An array of antenna elements 12 is driven by a transmitter 14. The feed current for each antenna element passes through a phase shifter 16. If the phase shifts implemented by the phase shifters 16 are all the same, the transmit waves from the array of antenna elements 16 combine to form a wavefront 18 perpendicular to the antenna axis 20. If the phase shifts of the phase shifters 16 gradually increase across the array (e.g., from the top to the bottom of the array in FIG. 1), the transmit waves from the array of antenna elements 16 combine to form a wavefront 22 directed at an angle θ relative to the antenna axis 20. In an exemplary one-dimensional array of antenna elements 16, the transmit EM beam can be steered in a single plane (e.g., the vertical plane) by varying the phase shift provided by each of the phase shifters 16.

[0004] The angle θ of the antenna beam can be changed by changing the phase shift of the individual phase shifters 16. Figure 2 shows a prior art example of a variable phase shifter 28 that can be used for this purpose. The variable phase shifter 28 consists of a wiper arm 36 that is rotatable about a pivot coupler 38, with the distal end of the wiper arm 36 scanning an arc-shaped conductive strip 40. The coupling between the distal end of the wiper arm 36 and the conductive strip 40 is capacitive. As the wiper arm 36 rotates about the pivot coupler 38, the path lengths between the first port 30 and the second port 32 and between the first port 30 and the third port 34 change, changing the phase of the signals output at the second port 32 and the third port 34. Summary of the Invention [Problem to be solved by the invention]

[0005] Because the phase shifter 28 shown in Figure 2 is a slider mechanism, the wiper arm 36 must be physically moved (e.g., rotated) to change the phase at the output port. To make the phase shifter of Figure 2 remotely controllable, a stepper motor or other such drive mechanism must be associated with the phase shifter's wiper arm. The mechanical nature of the phase shifter 28 and associated stepper motor can cause reliability and performance issues in the transmitter / antenna system. [Means for solving the problem]

[0006] In one aspect, the present invention may be a differential time delay shifter including a 1-to-N switch, where N is an integer greater than 1. The 1-to-N switch may have one pole contact, N throw contacts, and a pole arm configured to selectively electrically couple the pole contact with zero or more of the N throw contacts. One of the N throw contacts may be an initial throw contact in an initial (first) position of the 1-to-N switch, and one of the N throw contacts may be a final throw contact in a final position of the 1-to-N switch. The differential time delay shifter may further include one or more transmission lines, each electrically connected between two of the N throw contacts. The differential time delay shifter may further include a source configured to generate an electromagnetic (EM) signal. The source may be electrically coupled to the pole contacts to transmit the EM signal to the pole contacts. The differential time delay shifter may further include one or more loads, a first load of which is electrically coupled to the first throw contact.

[0007] In one embodiment, a second load of the one or more loads may be electrically coupled to the last throw contact. The switch positions of the 1-to-N switch are such that (i) the EM signal propagates through M of the one or more transmission lines to the first load and (ii) the EM signal propagates through NM of the one or more transmission lines to the second load, where M may be an integer greater than or equal to 0. The M transmission lines may be different from the NM transmission lines. The pole arm may be configured to selectively electrically couple the pole contact to only one of the N throw contacts at a time. The pole arm may be configured to selectively electrically couple the pole contact to two or more of the N throw contacts simultaneously. The pole arm may be configured to (i) selectively electrically couple to none of the N throw contacts, (ii) selectively electrically couple to only one of the N throw contacts at a time, or (iii) selectively electrically couple to two or more of the N throw contacts simultaneously.

[0008] The differential time delay shifter may further comprise one or more matching components configured to match an impedance of one of the switch, the load, the source, and the one or more transmission lines to an impedance of another of the switch, the load, the source, and the one or more transmission lines.

[0009] In another aspect, a method of applying a time delay to an electromagnetic (EM) signal may include configuring a 1:N switch to include: (i) one pole contact, (ii) N throw contacts, (iii) a pole arm configured to selectively electrically couple the pole contact to one of the N throw contacts, where one of the N throw contacts is an initial throw contact in an initial position of the 1:N switch and one of the N throw contacts is a final throw contact in an initial position of the 1:N switch, where N is an integer greater than 1, and (iv) one or more transmission lines, each of which is electrically connected between two of the N throw contacts, where N is an integer greater than 1. The method may further include electrically coupling a source configured to generate an electromagnetic (EM) signal to the pole contacts, electrically coupling a first load to the first throw contact, and operating the pole arm to electrically couple the pole contact to one of the N throw contacts.

[0010] The method may further include electrically coupling a second load to the last throw contact. The method may further include causing the EM signal to propagate through M of the one or more transmission lines to the first load and causing the EM signal to propagate through N M of the one or more transmission lines to the second load, where M is an integer greater than or equal to 0. The method may further include selectively electrically coupling the pole contact to only one of the N throw contacts at a time. The method may also include selectively electrically coupling the pole contact to two or more of the N throw contacts simultaneously. The method may alternatively include (i) selectively electrically coupling the pole contact to none of the N throw contacts, (ii) selectively electrically coupling the pole contact to only one of the N throw contacts at a time, or (iii) selectively electrically coupling the pole contact to two or more of the N throw contacts simultaneously.

[0011] In yet another aspect, an antenna array feed system may include an antenna array having at least one column of radiating elements and at least one delay-shift network configured to distribute an electromagnetic (EM) signal to the antenna array. The at least one delay-shift network may include at least one 1:N switch and one or more transmission lines, each of the transmission lines electrically connected between two of the N throw contacts of the 1:N switch. Each of the radiating elements of the antenna array may be electrically coupled to the throw contacts of the at least one 1:N switch, and each radiating element may be located at an end point of the one or more transmission lines.

[0012] In embodiments, the 1-to-N switch may be configured to selectively electrically couple the EM signal to only one of the N throw contacts at a time. The 1-to-N switch may be configured to selectively electrically couple the EM signal to two or more of the N throw contacts simultaneously. The 1-to-N switch may be configured to selectively electrically couple the EM signal to (i) none of the N throw contacts, (ii) only one of the N throw contacts at a time, or (iii) two or more of the N throw contacts simultaneously.

[0013] The antenna array may be comprised of at least two columns of radiating elements. The at least one delay shift network may be configured to distribute the EM signal to the at least two columns of radiating elements such that elements in each column experience the same differential delay pattern. The antenna array may be comprised of at least two columns of radiating elements. The at least one delay shift network may be configured to distribute the EM signal to the at least two columns of radiating elements such that elements in each column experience a different differential delay pattern.

[0014] The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.

[0015] The foregoing will become apparent from the following description, which shows exemplary embodiments in greater detail. In the accompanying drawings, like reference characters refer to like parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the embodiments. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a diagram showing a prior art example of a phased array antenna system. [Figure 2] FIG. 2 shows a prior art example of a variable phase shifter. [Figure 3] FIG. 3 is an exemplary embodiment of a differential delay shifter according to the present invention. [Figure 4] FIG. 4 is a diagram showing an example of a simulation model of a differential delay shifter according to the present invention. [Figure 5A] FIG. 5A is a diagram showing simulation results related to the simulation model shown in FIG. [Figure 5B] FIG. 5B is a diagram showing simulation results related to the simulation model shown in FIG. [Figure 6A] FIG. 6A illustrates an alternative embodiment of a differential delay shifter in accordance with the present invention. [Figure 6B] FIG. 6B illustrates an alternative embodiment of a differential delay shifter in accordance with the present invention. [Figure 6C] FIG. 6C illustrates an alternative embodiment of a differential delay shifter in accordance with the present invention. [Figure 6D] FIG. 6D illustrates an alternative embodiment of a differential delay shifter in accordance with the present invention. [Figure 7] FIG. 7 shows an example of a cascaded network of delay shifts that can be used to steer two axes of a multi-element array. DETAILED DESCRIPTION OF THE INVENTION

[0017] Exemplary embodiments are described below.

[0018] The described embodiments relate to a differential true time delay shifter that can provide a discrete time delay path from an electromagnetic (EM) signal source to a load.

[0019] 3 illustrates an exemplary embodiment of a differential delay shifter according to the present invention, comprising a single-pole, four-throw switch 102, a first transmission line 104, a second transmission line 106, and a third transmission line 108. The switch 102 may include a pole 110 electrically coupled to a pole arm 112, the pole 112 being configured to be selectively coupled to one of a first contact 114, a second contact 116, a third contact 118, and a fourth contact 120. The first transmission line 104 (TL1) is electrically coupled between the first contact 114 and the second contact 116. The second transmission line 106 is electrically coupled between the second contact 116 and the third contact 118. The third transmission line 108 is electrically coupled between the third contact 118 and the fourth contact 120. The source 122 (S1) is electrically coupled to the pole 110, the first load (L1) 124 is electrically coupled to the first contact 114, and the second load (L2) 126 is electrically coupled to the fourth contact 120.

[0020] When the switch 102 electrically couples the pole 110 to the first contact 114, there is (i) a direct transmission path from the source 122 to the first load 124, and (ii) a transmission path from the source 122 to the second load 126 via transmission lines TL1 104, TL2 106, and TL3 108.

[0021] When the switch 102 electrically couples the pole 110 to the second contact 116, a transmission path exists (i) from the source 122 to the first load 124 via the transmission line TL1 104, and (ii) from the source 122 to the second load 126 via the transmission lines TL2 106 and TL3 108.

[0022] When the switch 102 electrically couples the pole 110 to the third contact 118, a transmission path exists (i) from the source 122 to the first load 124 via the transmission lines TL1 104 and TL2 106, and (ii) from the source 122 to the second load 126 via the transmission line TL3 108.

[0023] When the switch 102 electrically couples the pole 110 to the fourth contact 120, there is (i) a transmission path from the source 122 to the first load 124 via the transmission lines TL1 104, TL2 106, and TL3 108, and (ii) a direct transmission path from the source 122 to the second load 126.

[0024] By setting the switch 102 to one of the four states described above, the transmission path from the source 122 to the first load 124 may be configured to be TL1, TL1+TL2, or TL1+TL2+TL3, and the transmission path from the source 122 to the second load 126 may be configured to be TL3, TL2+TL3, or TL1+TL2+TL3. Each transmission line TL1 104, TL2 106, TL3 108 implements a time delay for signals propagating through the transmission line. This delay is equal to the length of the transmission line divided by the propagation velocity of the signal through the transmission line. As a result, the phase delay of the propagating signal depends on the frequency (wavelength) of the signal. For example, a 24 mm (0.024 m) transmission line has a propagation velocity of c=3x10 8 If so, then 0.024m / (3x10 8 A time delay of 80 pS (m / s) results. For a 2 GHz propagating signal with a wavelength of 0.5 ns, a time delay of 80 pS corresponds to a phase delay of approximately 58°. Thus, the time delay resulting from a particular set of transmission paths selected by the switch will result in a corresponding phase delay. The switch 102 may be characterized by a fifth state in which the poles are not electrically coupled to any of the throw contacts and the poles are electrically isolated from the throw contacts.

[0025] The above examples are presented to illustrate the concepts of the present invention and are not intended to be limiting. Embodiments of the present invention may utilize any number of throws (e.g., a single-pole, N-throw switch, where N is an integer). The transmission lines between the throw contacts of the switch (e.g., TL1, TL2, TL3) may be of any length and need not necessarily be equal. The lengths of the transmission lines may be selected appropriately to achieve a desired propagation delay for a particular switch setting. Additional transmission line segments (matching segments) may be included in the differential delay shifter to provide impedance matching (i) between the transmission lines, (ii) from the switch 102 to the transmission line, (iii) from the source to the switch, and (iv) from the transmission line to the load. The matching segments may add length to the transmission path from the source 122 to the loads 124, 126, which corresponds to an increased phase delay in the load, as discussed above.

[0026] Referring to the exemplary embodiment described above with respect to FIG. 3, assume that the length of TL1 = the length of TL2 = the length of TL3 = 24 mm, and the signal driven by S1 has a frequency in the range of 0-4 GHz. When switch 112 connects pole 110 to first contact 114, the time delay difference between the signals at S1 122 and L1 124 will be 0 pS, and the time difference between the signals at S1 122 and L2 126 will be approximately 240 pS. When switch 112 connects pole 110 to second contact 114, the time difference between the signals at S1 122 and L1 124 will be approximately 80 pS, and the time difference between the signals at S1 122 and L2 126 will be approximately 160 pS. When switch 102 connects pole 110 to third contact 116, the time difference between the signals at S1 122 and L1 124 will be approximately 160 pS, and the time difference between the signals at S1 122 and L2 126 will be approximately 80 pS. When switch 102 connects pole 110 to fourth contact 118, the time difference between the signals at S1 122 and L1 124 will be approximately 240 pS, and the time difference between the signals at S1 122 and L2 126 will be approximately 0 pS. The above-described example implementations are summarized in Table 1.

[0027] [Table 1]

[0028] 4 shows an example simulation model of a differential delay shifter including a 1-pole, 4-throw switch 202 that distributes a signal from a source P3 222 to a first load P1 224 and a second load P2 226. The first and second loads 224, 226 in this exemplary embodiment are depicted as 100 ohm impedance loads, and the source 222 is depicted as a 50 ohm impedance load, although these specific values ​​are illustrative and not intended to be limiting. The switch 202 in this example simulation model is a Menlo Microsystems, Inc. MM5130 switch, featuring a 1-pole, 4-throw switching mechanism. The first transmission line 204 comprises a 12 mm, 100 Ω transmission line (Line 8) and two matching segments (Line 9 and Line 3), each with an impedance of Z = zm (matching impedance) and a length of lm (matching length). The second transmission line 206 consists of a 12 mm, 100 Ω transmission line (Line 5) and two matching segments (Line 1, Line 2). The third transmission line 208 comprises a 12 mm, 100 Ω transmission line (Line 7) and two matching segments (Line 4 and Line 11). The matching segment 230 matches the first load 224 to the first segment 204 and to the switch 202. The matching segment 232 matches the second load 226 to the third segment 208 and to the switch 202. The matching segment 234 matches the source 222 to the switch 202.

[0029] 5A and 5B illustrate simulation results associated with the simulation model shown in FIG. 4. FIG. 5A shows the transmission loss 502 (dB(S[2,3])) between the source 222 and the first load 224 and the transmission loss 504 (dB(S[3,1])) between the source 222 and the second load 226, representing a near equal division of power (3 dB). FIG. 5B shows the time delay difference between the first load 224 and the second load 226 as a function of frequency for each of four switch positions 506, 508, 510, and 512.

[0030] The described embodiment is a discretized or quantized version of the wiper arm phase shifter described with respect to Figure 2. However, the described embodiment provides substantially improved performance at high frequencies (e.g., greater than 1 GHz).

[0031] Smaller switches (e.g., the 1-pole, 4-throw switches used in the exemplary embodiments shown in FIGS. 3 and 4 ) may instead be combined to form larger switches, as shown in the exemplary embodiments of FIGS. 6A and 6B , although a single switch device with a higher number of throw contacts (e.g., 8, 16, or 32 throw contacts) may be used. FIG. 6A illustrates combining two 1-pole, 4-throw switches to form an effective 1-pole, 8-throw switch with correspondingly more transmission lines, increasing the number of selectable phase delays. Similarly, FIG. 6B illustrates combining four 1-pole, 4-throw switches to form an effective 1-pole, 16-throw switch. Configurations such as those shown in the exemplary embodiments of FIGS. 6A and 6B require each individual switch to enable a fifth “no contact” state in which the pole contact is isolated from any throw contact, such that only one switch is active at any time, electrically connecting its pole contact to the throw contact.

[0032] As noted above, some embodiments may provide for only one switch being active at a given time, but alternative embodiments may take advantage of the system to close multiple switches at a given time, thereby creating additional phase states that are not available when only one switch is active. Similarly, configurations in which no switches are active can disconnect antenna elements, thereby creating new antenna patterns that are not available when at least one element is connected to a transmitting source.

[0033] While the discrete (i.e., quantized) versions of the phase shifters described herein may be used to activate multiple switches as described above, actual wiper arm phase shifters cannot facilitate similar states. In other words, prior art wiper arm phase shifters can only implement one wiper position at a time, which corresponds to the activation of one switch in the described embodiments of the discrete phase shifter. Wiper arm phase shifters are mechanical and cannot simultaneously contact the toe points on the delay line. Therefore, the implementation of more than one switch in a discrete phase shifter is not, and could not be, anticipated in the prior art.

[0034] When two switch paths are closed simultaneously, they connect adjacent nodes of the transmission line together, so the section of the transmission line between these nodes becomes a parasitic element in the circuit. This can be thought of as an open-circuited stub line with half the length of the loop between the adjacent nodes and an impedance of Zo / 2 (Zo is the impedance through the transmission line). If the delay loop length is about a quarter wavelength or less (which corresponds to a 90-degree phase step), the parasitic effects of the open-circuited stub can be easily adjusted. Phase differences of more than 90 degrees reduce the effectiveness of this technique. In practice, phase steps are typically smaller than 90 degrees, so this is not a significant limitation.

[0035] The differential delay shift networks described herein are not limited to providing adjustment or beam steering in a single axis of an array of antenna elements. As shown in the exemplary embodiment of FIG. 7, cascaded delay shift networks may be used to steer two axes of a multi-element array 702 having two columns of four elements each. In this embodiment, both azimuth and elevation are adjusted. A first delay shift network 704 allows control of the relative signal delays feeding the individual columns of elements, thereby providing azimuth beam steering. Within each column, elevation beam steering is provided by additional delay shift networks driven by RF signal 705. A first output RF signal 707a from the first delay shift network 704 is provided to a first coupler 742, which splits the first output RF signal 707a and distributes versions of that signal to a first outer elevation delay shift network 706 and a first inner elevation delay shift network 708. The second output RF signal 707b from the first delay shift network 704 is provided to a second combiner 744, which splits the second output RF signal 707b and distributes versions of that signal to a second outer elevation delay shift network 712 and a second inner elevation delay shift network 710.

[0036] In an exemplary embodiment having four radiating elements in each column, each column is composed of two outer elements (e.g., elements 720 and 728 in the first column, and elements 730 and 738 in the second column) and two inner elements (e.g., elements 722 and 724 in the first column, and elements 732 and 734 in the second column). A first outer elevation delay shift network 706 drives the two outer elevation elements 720 and 728 in the first column, and a second outer elevation delay shift network 712 drives the two outer elevation elements 730 and 738 in the second column. Similarly, a first inward elevation delay shift network 708 drives two inward elevation elements 722 and 724 in the first row, and a second inward elevation delay shift network 710 drives two outward elevation elements 732 and 734 in the second row.

[0037] Typically, each column will be controlled to experience the same differential delay, but the columns can be set to different elevation angles depending on the required radiation pattern by individually adjusting the delay shifters.

[0038] Exemplary embodiments of the present invention may implement switch 102 using a microelectromechanical systems (MEMS) switch having a low-parasitic, all-series switch element (e.g., the MM5130 switch described herein). Such a MEMS switch significantly simplifies circuit implementation compared to using more conventional solid-state switches incorporating shunt circuit elements. While the use of MEMS switches may offer certain advantages, the exemplary use of such a MEMS switch-based architecture is not intended to be so limited.

[0039] The switch-based embodiment of the differential delay shifter described herein has not been described in the prior art because deployed antenna installations typically operate as frequency division duplexers (FDD). FDD systems can simultaneously transmit and receive signals, requiring mitigation of nonlinearities to control passive intermodulation (PIM). Because ohmic switch contacts can result in significant nonlinearities, resulting in unacceptably high PIM values, switch-based phase shifters have traditionally been implemented with capacitively coupled sliders, as shown herein. Thus, switch-based phase shifter mechanisms are not considered for antenna installation because the nonlinearities are incompatible with FDD systems.

[0040] Because emerging cellular architectures (e.g., 5G systems) may utilize time division duplex (TDD) communications in which EM signals are not simultaneously transmitted and received, embodiments of the switch-based differential delay shifters described herein may have practical utility in antenna downtilt applications.

[0041] While exemplary embodiments have been particularly shown and described, it will be understood by those skilled in the art that various changes in form and details can be made therein without departing from the scope of the embodiments encompassed by the appended claims. The present invention includes the following aspects. [Aspect 1] A differential time delay shifter, the differential time delay shifter comprising: A 1:N switch (N is an integer greater than 1), One polar contact and N throwing contacts, a pole arm configured to selectively electrically couple a pole contact to zero or more of the N throw contacts; Among the N throw contacts, one throw contact is a first throw contact in a first position of the 1:N switch; a 1:N switch, one of the N throw contacts being the last throw contact in the last position of the 1:N switch; one or more transmission lines, each of which electrically connects two of the N throw contacts; a source configured to generate an electromagnetic (EM) signal, the source electrically coupled to the pole contact to transmit the electromagnetic signal to the pole contact; one or more loads, a first load electrically coupled to the first throw contact; 1. A differential time delay shifter comprising: [Aspect 2] 2. The differential time delay shifter of claim 1, wherein a second load of the one or more loads is electrically coupled to the last throw contact. Aspect 3 In the differential time delay shifter according to aspect 1, the switch positions of the 1-to-N switches are: (i) propagating the EM signal through M of the one or more transmission lines (M is an integer greater than or equal to 0) to the first load; (ii) a differential time delay shifter that propagates the EM signal through NM of the one or more transmission lines to the second load; Aspect 4 2. The differential time delay shifter according to claim 1, wherein the M transmission lines are different from the NM transmission lines. Aspect 5 2. The differential time delay shifter of claim 1, wherein the pole arm is configured to selectively electrically couple the pole contact to only one of the N throw contacts at a time. Aspect 6 2. The differential time delay shifter of claim 1, wherein the pole arms are configured to selectively electrically couple the pole contacts to two or more of the N throw contacts simultaneously. Aspect 7 2. The differential time delay shifter according to claim 1, wherein the pole arms include the pole contacts: (i) not selectively electrically coupled to any of the N throw contacts; (ii) selectively electrically coupling to only one of said N throw contacts at a time; or (iii) a differential time delay shifter configured to simultaneously selectively electrically couple to two or more of the N throw contacts; Aspect 8 10. The differential time delay shifter of claim 1, further comprising one or more matching components configured to match an impedance of one of the switch, the load, the source, and the one or more transmission lines to an impedance of another of the switch, the load, the source, and the one or more transmission lines. Aspect 9 1. A method for applying a time delay to an electromagnetic (EM) signal, comprising: A 1-to-N switch (where N is an integer greater than 1) (i) one polar contact; (ii) N throwing contacts; (iii) a pole arm configured to selectively electrically couple the pole contact to one of the N throw contacts, wherein one of the N throw contacts is a first throw contact in a first position of the 1:N switch and one of the N throw contacts is a last throw contact in a last position of the 1:N switch; and (iv) configuring the 1:N switch to include one or more transmission lines, each transmission line electrically connected between two of the N throw contacts; electrically coupling a source configured to generate an electromagnetic (EM) signal to the pole contact; electrically coupling a first load to the first throw contact; and manipulating the pole arm so that the pole contact is electrically coupled to one of the N throw contacts. Aspect 10 10. The method of claim 9, further comprising electrically coupling a second load to the last throw contact. Aspect 11 10. The method of claim 9, further comprising propagating the EM signal to the first load through M of the one or more transmission lines (M is an integer greater than or equal to 0), and propagating the EM signal to the second load through NM of the one or more transmission lines. Aspect 12 10. The method of claim 9, further comprising selectively electrically coupling the pole contact to only one of the N throw contacts at a time. Aspect 13 10. The method of claim 9, further comprising selectively electrically coupling the pole contact to two or more of the N throw contacts simultaneously. Aspect 14 In the method of claim 9, the method further includes selectively electrically coupling the pole contact to (i) none of the N throw contacts, (ii) only one of the N throw contacts at a time, or (iii) two or more of the N throw contacts simultaneously. Aspect 15 1. An antenna array feed system comprising: an antenna array having at least one row of radiating elements; at least one delay shift network configured to distribute an electromagnetic (EM) signal to the antenna array; (i) at least one 1:N switch; (ii) one or more transmission lines, each transmission line electrically connected between two of the N throw contacts of the 1:N switch; at least one delay-shift network, each of the radiating elements of the antenna array, the radiating element being electrically coupled to a throw contact of the at least one 1:N switch and positioned at an end point of the one or more transmission lines; an antenna array feed system comprising: Aspect 16 In the antenna array feed system of aspect 15, the 1 to N switch is configured to selectively electrically couple the EM signal to only one of the N throw contacts at a time. Aspect 17 In the antenna array feed system of aspect 15, the 1 to N switch is configured to selectively electrically couple the EM signal to two or more of the N throw contacts simultaneously. Aspect 18 In the antenna array feed system of aspect 15, the 1-to-N switch is configured to (i) selectively electrically couple the EM signal to none of the N throw contacts, (ii) selectively electrically couple the EM signal to only one of the N throw contacts at a time, or (iii) selectively electrically couple the EM signal to two or more of the N throw contacts simultaneously. Aspect 19 In the antenna array feed system of aspect 15, the antenna array includes at least two columns of radiating elements, and the at least one delay shift network is configured to distribute the EM signal to the at least two columns of radiating elements so that elements in each column experience the same differential delay pattern. Aspect 20 In the antenna array feed system of aspect 15, the antenna array includes at least two columns of radiating elements, and the at least one delay shift network is configured to distribute the EM signal to the at least two columns of radiating elements such that elements in each column experience a different differential delay pattern.

Claims

1. A differential time delay shifter, the differential time delay shifter comprising: A 1-to-N switch (N is an integer greater than 1), One polar contact; N throwing contacts; a pole arm configured to selectively electrically couple a pole contact to zero or more of the N throw contacts; Among the N throw contacts, one throw contact is a first throw contact in a first position of the 1:N switch, a one-to-N switch, one of the N throw contacts being the last throw contact in the last position of the one-to-N switch; one or more transmission lines, each of which electrically connects two adjacent ones of the N throw contacts; a source configured to generate an electromagnetic (EM) signal, the source electrically coupled to the pole contact to transmit the EM signal to the pole contact; one or more loads, a first load electrically coupled to the first throw contact; one or more matching components configured to match impedances between one element and another element selected from a group of elements consisting of the 1:N switch, the first load of the one or more loads, the source, and the one or more transmission lines; 1. A differential time delay shifter comprising:

2. 2. The differential time delay shifter of claim 1, wherein a second load of the one or more loads is electrically coupled to the last throw contact.

3. 3. The differential time delay shifter according to claim 2, wherein the switch positions of the 1:N switch are: (i) propagating the EM signal through M of the one or more transmission lines (M is an integer greater than or equal to 0) to the first load; (ii) a differential time delay shifter that propagates the EM signal through N−M−1 of the one or more transmission lines to the second load;

4. 4. The differential time delay shifter of claim 3, wherein said M transmission lines are different from said N-M-1 transmission lines.

5. 2. The differential time delay shifter of claim 1, wherein said pole arms are configured to selectively electrically couple said pole contacts to only one of said N throw contacts at a time.

6. 2. The differential time delay shifter of claim 1, wherein said pole arms are configured to selectively electrically couple said pole contacts to two or more of said N throw contacts simultaneously.

7. 2. The differential time delay shifter of claim 1, wherein said pole arms are arranged to connect said pole contacts to: (i) not selectively electrically coupled to any of the N throw contacts; (ii) selectively electrically coupling to only one of said N throw contacts at a time; or (iii) a differential time delay shifter configured to simultaneously selectively electrically couple to two or more of said N throw contacts;

8. 1. A method of applying a time delay to an electromagnetic (EM) signal, comprising: A 1-to-N switch (N is an integer greater than 1) (i) one polar contact; (ii) N throwing contacts; (iii) a pole arm configured to selectively electrically couple the pole contact to one of the N throw contacts, wherein one of the N throw contacts is a first throw contact in a first position of the one-to-N switch, and one of the N throw contacts is a last throw contact in a last position of the one-to-N switch; and (iv) configuring the 1:N switch to include one or more transmission lines, each of which is electrically connected between two adjacent ones of the N throw contacts; electrically coupling a source configured to generate an electromagnetic (EM) signal to the pole contact; electrically coupling a first load to the first throw contact; manipulating the pole arm so that the pole contact is electrically coupled to one of the N throw contacts; incorporating one or more matching components configured to match impedances between one element and another element selected from a group of elements consisting of the 1:N switch, the first load, the source, and the one or more transmission lines; A method comprising:

9. 9. The method of claim 8, further comprising electrically coupling a second load to the last throw contact.

10. 10. The method of claim 9, further comprising propagating the EM signal through M numbers of the one or more transmission lines, where M is an integer greater than or equal to 0, to the first load, and propagating the EM signal through N-M-1 numbers of the one or more transmission lines to the second load.

11. 9. The method of claim 8, further comprising selectively electrically coupling the pole contact to only one of the N throw contacts at a time.

12. 9. The method of claim 8, further comprising selectively electrically coupling the pole contact to two or more of the N throw contacts simultaneously.

13. 9. The method of claim 8, further comprising: (i) selectively electrically coupling the pole contact to none of the N throw contacts, (ii) selectively electrically coupling the pole contact to only one of the N throw contacts at a time, or (iii) simultaneously selectively electrically coupling the pole contact to two or more of the N throw contacts.

14. 1. An antenna array feed system comprising: an antenna array having at least one row of radiating elements; at least one delay-shift network configured to distribute an electromagnetic (EM) signal to an antenna array, (i) at least one 1:N switch; (ii) one or more transmission lines, each of which is electrically connected between two adjacent ones of the N throw contacts of the 1:N switch; at least one delay shift network comprising: a source configured to generate the EM signal, the source electrically connected to a pole contact of the 1:N switch to transmit the EM signal to the pole contact; one or more matching components configured to match impedances between one element and another element selected from a group of elements consisting of the at least one 1:N switch, one of the radiating elements of the antenna array, the source, and the one or more transmission lines; each of the radiating elements of the antenna array, the radiating element being electrically coupled to a throw contact of the at least one 1:N switch and positioned at an end point of the one or more transmission lines; an antenna array feed system comprising:

15. 15. The antenna array feed system of claim 14, wherein the 1-to-N switch is configured to selectively electrically couple the EM signal to only one of the N throw contacts at a time.

16. 15. The antenna array feed system of claim 14, wherein the 1-to-N switch is configured to selectively electrically couple the EM signal to two or more of the N throw contacts simultaneously.

17. 15. The antenna array feed system of claim 14, wherein the 1-to-N switch is configured to (i) selectively electrically couple the EM signal to none of the N throw contacts, (ii) selectively electrically couple the EM signal to only one of the N throw contacts at a time, or (iii) simultaneously selectively electrically couple the EM signal to two or more of the N throw contacts.

18. 15. The antenna array feed system of claim 14, wherein the antenna array includes at least two columns of radiating elements, and wherein the at least one delay-shift network is configured to distribute the EM signal to the at least two columns of radiating elements so that elements in each column experience the same differential delay pattern.

19. 15. The antenna array feed system of claim 14, wherein the antenna array includes at least two columns of radiating elements, and wherein the at least one delay-shift network is configured to distribute the EM signal to the at least two columns of radiating elements such that elements in each column experience a different differential delay pattern.

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