Mass-related phase shifter network

Abstract

Comprehensive phase shifter network: a two-port cross-circuit with a first capacitor that couples a first circuit node to a second circuit node, a second capacitor that couples a third circuit node to a fourth circuit node, and a first inductor that couples the first circuit node to the fourth circuit node, a first coupled section with a first conductor that couples a ground-referenced input node to the first circuit node, and a second conductor that is connected between a circuit ground and the third circuit node, the second conductor being inductively coupled to the first conductor, and a second coupled section with a third conductor that couples a ground-referenced output node to the fourth circuit node, and a fourth conductor that is connected between the circuit ground and the second circuit node, the fourth conductor being inductively coupled to the third conductor.

Description

Background of the Revelation

[0001] An all-pass phase-shift network is an electrical circuit that ideally passes all operating frequencies with constant amplitude, but modifies the phase relationship over a frequency range. This variation in the phase relationship is achieved by varying the transmission delay of the phase-shift circuit with frequency. In other words, a phase-shift network provides a phase shift or delay without significantly altering the amplitude characteristics of the electrical signal passing through it. Therefore, a phase-shift network can be useful in a variety of electronic applications.

[0002] Phase-shifting networks that address cutoff frequencies outside the bandwidth of interest are useful in high-frequency coupler circuits. Such networks can be used in various types of hybrid couplers or other directional coupler circuits. These networks are discussed in our earlier U.S. application, serial number 13 / 083,180, filed on April 8, 2011.

[0003] US Patent 3,560,894 A discloses a phase-shifting network comprising a cross-connection and a first coupled section with a first and a second conductor. US Patent 2005 / 0122,186 A1 discloses a phase-shifting network with a coupler arranged on opposite sides of a dielectric substrate. US Patent 2009 / 0134,953 A1 discloses a phase-shifting network and filter formed by thin-film layers on a substrate. Brief summary of the Revelation

[0004] A phase-shifting network can include a two-port crossover that couples a first coupled section to a second coupled section. The two-port crossover can include a first capacitor coupling a first circuit node to a second circuit node, a second capacitor coupling a third circuit node to a fourth circuit node, and a first inductor coupling the first circuit node to the fourth circuit node. The first coupled section can include a first conductor coupling a ground-referenced input node to the first circuit node, and a second conductor connected between a circuit ground and the third circuit node. The second conductor can be inductively coupled to the first conductor.Similarly, the second coupled section can include a third conductor that couples a ground-referenced output node to the fourth circuit node, and a fourth conductor connected between the circuit ground and the second circuit node. The fourth conductor can be inductively coupled to the third conductor.

[0005] The first and second conductors can form a first transmission line, and the third and fourth conductors can form a second transmission line. These transmission lines can be, for example, coaxial or planar transmission lines.

[0006] The first coupled section may further include a fifth conductor connected electrically in parallel to the second conductor, and the second coupled section may further include a sixth conductor connected electrically in parallel to the fourth conductor. In some examples, the first and second coupled sections may be striplines.

[0007] In another example, a phase difference network can include a signal divider to split a ground-referenced input signal into a first and a second preliminary ground-referenced signal. A first phase-shifting network could respond to the first preliminary ground-referenced signal to produce a ground-referenced output signal with a first phase that varies frequency-dependently over a given frequency range. A second phase-shifting network could respond to the second preliminary ground-referenced signal to produce a ground-referenced output signal with a second phase that varies frequency-dependently and differs from the first phase by a certain amount, which is essentially constant over the given frequency range. Brief description of the drawings Fig. Figure 1 is a general circuit diagram showing an example of a mass-referenced phase-shifting network. Fig. Figure 2 is a representation of an example of a printed circuit, known as the phase-shifting network from Fig. 1 can be used. Fig. Figure 3 is an isometric view of the printed circuit board. Fig. 2. Fig. 4 is a block diagram of an example of a phase difference network, which is the phase shifter network from Fig. can include 1. Fig. 5 is a diagram that represents the phase difference network. Fig. 4 represents a phase shift as a function of frequency. Fig. 6 is a diagram showing a phase difference over a bandwidth of interest for the two outputs of the in Fig. 4 represents the phase difference network shown. Detailed description of embodiments

[0008] With reference to Fig. A phase-shifting network, generally shown as 10, can connect an external ground-referenced (asymmetric) source at a source or input node 12 with a ground-referenced (asymmetric) load at a load or output node 14. The phase-shifting network 10 can include an input line 16 connected to the source node 12 and an output line 18 connected to the load node 14. A high-pass filter 20 can be connected downstream of the input line 16. A phase-shifting circuit 22 can be connected between the high-pass filter 20 and the output line 18.

[0009] The high-pass circuit 20 can include two longitudinally connected capacitors 24 and 26. An electrical node 28 extending between the capacitors 24 and 26 can be bridged to the circuit ground 30 by a coil 32 to complete this example of a high-pass circuit 20.

[0010] The phase-shifting circuit 22 can comprise a modified two-port crossover 34 extending between two diagonally symmetrically coupled sections 36 and 38. In general, the phase-shifting circuit 22, and in particular the coupled section 36, can be coupled to the high-pass circuit 20 via an input circuit node 40. The coupled section 36 can be coupled to the two-port crossover 34 via an input network node 42. The two-port crossover 34 can, in turn, be coupled to the coupled section 38 via an output network node 44.

[0011] The two-port cross-connection 34 can include a first series-connecting capacitor 46, which connects node 42 to a second output network node 48. A second series-connecting capacitor 50 can couple a second input network node 52 to the output network node 44. A cross-connecting inductor 54 can cross-connect a first terminal of capacitor 46 at node 42 to a second terminal of capacitor 50 at network node 44.

[0012] The coupled section 36 can comprise a coaxial transmission line 56 with an inner conductor 58 connecting node 40 to node 42, and a shield or outer conductor 60 connecting node 52 to the ground of the circuit 30. The coupled section 36 can also include a third conductor 62, which is electrically parallel to the outer conductor 60 between node 52 and the ground of the circuit. As is generally known, the conductors of a transmission line, such as conductors 58 and 60 of the transmission line 56, are inductively coupled. Other arrangements that provide inductive coupling between conductors can also be used.

[0013] The coupled section 38 can comprise a coaxial transmission line 64 with an inner conductor 66 connecting node 44 to output node 14 via the supply line 18, and a shield or outer conductor 68 connecting node 48 to the circuit ground 30. The coupled section 36 can also comprise a third conductor 70 electrically parallel to the outer conductor 68 between node 48 and the circuit ground.

[0014] It is thus evident that capacitor 46 can connect the inner conductor of coaxial transmission line 56 to the outer conductor of coaxial transmission line 64. Capacitor 50 can connect the outer conductor of coaxial transmission line 56 to the inner conductor of coaxial transmission line 64. The third conductors 62 and 70 can also be conductors of transmission lines 72 and 74, respectively, which have a high impedance relative to the circuit ground.

[0015] The triple-conductor arrangements of these examples for coupled sections 36 and 38 and the modified two-port cross-circuit 34 can together form a circuit whose electrical response is equal to or similar to that of a conventional two-port cross-circuit supplied over a full bandwidth of interest by means of ideal baluns.

[0016] Another embodiment for realizing a phase-shifting network 10 is a phase-shifting network 80, which in one example is represented by Fig. 2 and Fig. The diagram shows three metal coatings of a printed circuit board. Fig. 2 is a top view and Fig. Figure 3 is an isometric view of the phase-shifting network 80. In principle, the phase-shifting network 80 in this example can comprise three metallization layers 82, 84, 86 arranged over a base plate 88. The uppermost and lowermost metallization layers 82 and 86 can have almost the same layout (with some exceptions), whereas the middle layer 84 in Fig. 2 and Fig. 3 can be visually considered the thinner metallization layer. The uppermost metallization layer 82 is in Fig. 2 shown with solid lines.

[0017] All metallization layers can be separated by suitable substrates 90, 92, 94, 96, which have thicknesses and dielectric constants appropriate for the designed application. The dielectric substrates are not shown but are represented by the layers separated by dash-double-dot lines drawn around the corresponding metallization layer shown. The uppermost metallization layer 82 is arranged between substrates 90 and 92, the intermediate or middle metallization layer 84 is arranged between substrates 92 and 94, the lowermost metallization layer 86 is arranged between substrates 94 and 96, and the base plate 88 covers the lower surface of substrate 96. Connections between the uppermost and lowermost metallization layers are provided via through-contacts 98. Through-contacts 100 connect the metallization layers 82 and 86 to the base plate 88.Through contacts 102 provide connections between metal coatings on two adjacent layers, such as between the metallization layers 82 and 84. It is evident that the metal coating layout is compact and symmetrical and allows signal propagation in any direction between corresponding pairs of input and output nodes.

[0018] From the left side of the drawings in Fig. 2 and Fig. 3 can be a mass-related connection or an input node 104 to the middle layer 84. Similarly, from the right side of the drawings in Fig. 2 and Fig. 3 a mass-related connection or an output node 106 to the middle layer must be established.

[0019] Starting from node 104, the three metallization layers form an input line 108 in the form of a stripline corresponding to the input line 16. Each stripline has a narrow, flat inner conductor from metallization layer 84, which is arranged between two wider, flat outer conductors formed in metallization layers 82 and 86 and is inductively coupled to them over a planar area. A high-pass filter 110, corresponding to high-pass filter 20, can be connected downstream of the input line 108. A coupled section designed as a stripline in the form of a triple-conductor arrangement 112 can be connected between the high-pass filter 110 and a modified two-port crossover 114, corresponding to two-port crossover 34.A second coupled section, in the form of a second triple-wire arrangement 116 or a stripline, connects the two-port crossover 114 to an output supply line 118, which is also configured as a stripline. The triple-wire arrangement 116 and the output supply line 118 are to be considered as a continuous stripline. The output supply line 118 can connect the triple-wire arrangement 116 to the output node 106.

[0020] The high-pass circuit 110 can use surface-mounted capacitors 120 and 122 (as dashed boxes in Fig. 2 shown) and comprise an air coil 124. The capacitors 120 and 122 can be connected in series with the middle metallization layer of the circuit board, whereas the coil 124 can connect a contact point or node 126 located between the capacitor 120 and the capacitor 122 to a ground point 128 connected to the base plate 88 via the through contacts 100.

[0021] The high-pass circuit 110 can be connected to the triple-conductor arrangement 112 at a circuit node 130. The triple-conductor arrangement 112 can comprise a middle metal-coated conductor 132, a top metal-coated conductor 134, and a bottom metal-coated conductor 136. The ends of conductors 134 and 136 located near the high-pass circuit 110 are connected to the base plate 88 via the ground-connecting through contacts 100.

[0022] The two-port cross-circuit 114 can use surface-mounted capacitors 138 and 140 (as dashed boxes in Fig. 2) and comprise a printed spiral coil 142 formed from metal coatings on metal-coated layers 82 and 84 together with suitable non-ground-connecting through contacts 102. The capacitor 138 connects the middle metal-coated conductor 132 at a node 144 to the uppermost metal-coated conductor 146 at a node 146. The capacitor 140 connects the uppermost metal-coated conductor 134 at a node 148 to a node 150.

[0023] The triple-conductor arrangement 116 can comprise a middle metal-coated conductor 152 and uppermost and lowermost metal-coated conductors 154 and 156. The middle metal-coated conductor 152 is connected to node 150, and the uppermost and lowermost metal-coated conductors 154 and 156 are connected to node 146. Two through-contacts 100 located near the output lead 118 connect the metal-coated conductors 154 and 156 to the base plate.

[0024] The printed structures in the phase-shifting network 80 generate scattered capacitive and inductive parasitic effects, which can be analyzed using suitable electromagnetic simulation tools. It is therefore evident that the phase-shifting network 80 can be implemented in a compact three-layer structure, such as a printed circuit board. Other structures and embodiments are also obvious to those skilled in the art.

[0025] The phase-shifting network 80, and by reference accordingly the phase-shifting network 10, can be used as components in other circuits. For example, in Fig. Figure 4 shows an example of a phase difference network 170 that can be formed with at least one phase shifter network 10. The phase difference network 170 can include a signal divider 172 with an input 174 for receiving a ground-referenced (asymmetric) input signal and two outputs 176 and 178 for transmitting two ground-referenced (asymmetric) intermediate signals. A phase shifter network can be cascaded to each output of the divider 172. In particular, a phase shifter network 180 can be connected to output 176 and a phase shifter network 182 to output 178, all in a ground-referenced (asymmetric) manner. As mentioned earlier, the phase shifter networks 180 and 182 can each comprise a phase shifter network 10 or 180, as described above. The phase shifter networks 180 and 182 can generate respective output signals 184 and 186.

[0026] The phase difference network 170 can be configured to operate at a planned frequency or over a given frequency bandwidth. The phase difference network can generate output signals at outputs 184 and 186 that vary in phase and maintain a relatively constant phase difference between the output signals across the frequency range of interest.

[0027] In some examples, the phase shifting networks 180 and 182 can vary in phase angle from near zero at low frequencies to a higher value at high frequencies. The two phase shifting networks can often shift the phase angles of the corresponding output signals at outputs 184 and 186 by a constant. For example, the difference in phase angles of the two output signals across the bandwidth of interest of the phase difference network 170 can be close to or equal to 90 degrees.

[0028] In an example of a phase difference network 170, configured to operate within a 25-ohm environment in a frequency range of 20 MHz to 1000 MHz, the phase shifter network 180 can correspond to the configuration of the phase shifter network 10 or 80 and can therefore include the capacitors 24 and 26, each with approximately 618 pF, the inductor 32 with approximately 231 nH, the capacitors 46 and 50, each with approximately 22.5 pF, the inductor 54 with approximately 14 nH, the coaxial transmission lines 56 and 64, each with a characteristic impedance of 25 ohms, and the transmission lines 72 and 74, each with a characteristic impedance of 70 ohms.

[0029] In this example, the phase-shifting network 182 can be any phase-shifting network that provides a sufficiently constant phase difference with respect to the phase angle generated by the phase-shifting network 180. For example, the phase-shifting network 182 can comprise a conventional two-port cross-connection (not shown) with longitudinally connecting inductors of approximately 70 nH each and transversely connecting capacitors of approximately 106 pF each.

[0030] The phase-shifting network 182 can include one or more delay lines (not shown) which can be positioned appropriately within the phase-shifting network to add a corresponding, fixed phase offset to the connected signal path. A delay line has a fixed delay time. Therefore, it adds a phase shift that is linear with respect to frequency. In this embodiment, it is a cost-effective replacement for a two-port crossover or other low-delay network. For example, the phase-shifting network 182 can include a delay line connected to the conventional two-port crossover to provide a predetermined total phase shift suitable for generating the 90-degree phase difference relative to the phase angle of the phase-shifting network 180.

[0031] An example of the block diagram from Fig. Figure 4 was implemented using phase-shifting networks 180 and 182 with alternating delay maxima along the bandwidth of interest. A delay maximum is defined as the frequency at which the delay time generated by a network has a local maximum. A simple phase-shifting network can therefore have a single delay maximum. A more complex phase-shifting network can have multiple delay maxima.

[0032] For the frequency range of 20 MHz to 1000 MHz, the phase-shifting network 180 could ideally have rollover frequencies at approximately 15 MHz and 270 MHz, and the phase-shifting network 182 (not shown) could ideally have a rollover frequency at 70 MHz. A delay network provides the highest rollover frequency for network 182. A simulation of the phase-difference network 170 with the reactance values ​​given above yielded rollovers at approximately 13.3 MHz, 58.4 MHz, and 283.6 MHz.

[0033] If physically constructed, one embodiment of the phase-shifting network can generate 180 signals, which have phase angles determined by the in Fig. Figure 5 shows the solid upper line. As can be seen, the phase angle gradually shifts from approximately +40 degrees at 20 MHz to approximately -230 degrees at 1000 MHz. On the other hand, the phase-shifting network can generate 182 signals that exhibit the phase characteristics shown in Figure 5. Fig. Figure 5 shows the dashed lower line. As can be seen, the phase angle gradually shifts from -50 degrees at 20 MHz to approximately -320 degrees at 1000 MHz. Fig.Figure 6 illustrates the calculated phase difference of the two output signals at outputs 184 and 186. As can be seen, the phase difference is essentially constant, but varies between -81 degrees and -99 degrees over the frequency range from 20 MHz to 1000 MHz, which is approximately + / - 9 degrees from the nominal value of -90 degrees.

[0034] It is understood that the phase-shifting network described above demonstrates the phase-shifting characteristics of a two-port crossover without the frequency limitations and is inherently ground-referenced. Accordingly, this phase-shifting network can simultaneously exhibit ultra-wide or very high bandwidth and high power handling capabilities.

[0035] For thermal management reasons, the phase-shifting networks 10 and 80 can have a low insertion loss, which allows them to handle high power with limited heat dissipation. Furthermore, the described phase-shifting networks can be designed to be compact and reproducible for manufacturing purposes.

[0036] Mass-referenced phase-shifting networks 10 and 80 can be arranged within a phase-difference network, such as the phase-difference network 170, to create a three-interface component whose two output interfaces have essentially the same amplitude responses over a very wide bandwidth and phase responses separated by a predetermined value. The insertion loss of the three-interface component can be reduced, and the reflection losses at all three interfaces can also be reduced, so that the three-interface component can handle higher power over a wide bandwidth.

[0037] The above description is intended to be illustrative and not limiting. Many other embodiments will be obvious to the person skilled in the art after reviewing the above description. Accordingly, although embodiments of phase-shifting networks, a phase difference network, and phase-shifting methods have been shown and described in particular, many variations are possible. This disclosure may comprise one or more independent or interdependent inventions directed to different combinations of features, functions, elements, and / or properties. Other combinations and sub-combinations of features, functions, elements, and / or properties may be claimed.Such variations, whether directed to different combinations or to the same combinations, whether different, wider, narrower or the same in scope, are also considered to be covered by the subject matter of the present disclosure.

[0038] The foregoing embodiments are illustrative, and no single feature or element, or combination thereof, is necessary in all possible combinations. Where “a” or “a first” element, or the equivalent thereof, is cited, such expressions include one or more such elements, with two or more such elements neither required nor excluded. Furthermore, ordinal indicators, such as first, second, or third, are used for designated elements to distinguish between the elements and do not indicate any required or limited number of such elements, nor do they indicate any particular position or order of such elements, unless specifically stated otherwise.Ordinal indicators can be assigned to linked elements in the order in which they are introduced in a given context, and the ordinal indicators for such elements can be different in another context.

Claims

[1] Phase shifting network comprising: a two-port cross-connection having a first capacitor coupling a first circuit node to a second circuit node, a second capacitor coupling a third circuit node to a fourth circuit node, and a first coil coupling the first circuit node to the fourth circuit node, a first coupled section having a first conductor coupling a ground-referenced input node to the first circuit node, and a second conductor connected between a ground of the circuit and the third circuit node, the second conductor being inductively coupled to the first conductor, and a second coupled portion having a third conductor coupling a ground-referenced output node to the fourth circuit node, and a fourth conductor connected between the ground of the circuit and the second circuit node, the fourth conductor being inductively coupled to the third conductor. [2] Phase shifting network according to claim 1, characterized by that the first and second conductors form a first transmission line and the third and fourth conductors form a second transmission line. [3] Phase shifting network according to claim 2, characterized by that at least one of the first and second transmission lines is a coaxial transmission line. [4] Phase shifting network according to claim 2, characterized by that the first and second conductors are flat, surface-coupled conductors and the third and fourth conductors are flat, surface-coupled conductors. [5] Phase shifting network according to claim 1, characterized by that the first coupled portion further comprises a fifth conductor electrically connected in parallel with the second conductor, and the second coupled portion further comprises a sixth conductor electrically connected in parallel with the fourth conductor. [6] Phase shifting network according to claim 5, characterized by that the fifth conductor is also inductively coupled to the first conductor and the sixth conductor is also inductively coupled to the third conductor. [7] Phase shifting network according to claim 5, characterized by that the first and second coupled sections are striplines. [8] Phase shifting network according to claim 5, characterized by that the first and second conductors are the conductors of a first coaxial transmission line, and the third and fourth conductors are the conductors of a second coaxial transmission line. [9] Phase shifting network according to claim 1, characterized by that the first and second conductors are the conductors of a first coaxial transmission line, and the third and fourth conductors are the conductors of a second coaxial transmission line. [10] The phase shifting network of claim 1, further comprising a high-pass circuit coupling the input node to the first conductor. [11] Phase difference network comprising: a signal splitter for dividing a ground-referenced input signal into a first and a second preliminary ground-referenced signal, and a first and a second phase-shifting network, at least the first phase-shifting network being the phase-shifting network of claim 1 and responsive to the first preliminary ground-referenced signal to produce a ground-referenced output signal having a first phase that varies frequency-dependently over a certain frequency range, and the second phase shifting network is responsive to the second preliminary ground-referenced signal to produce a ground-referenced output signal having a second phase that varies with frequency and is different from the first phase by a predetermined amount that is substantially constant over the predetermined frequency range.

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