CN102509840A - Broadband Air Microstrip High Isolation Radial Power Combining Amplifier - Google Patents

Abstract

The invention provides a broadband air microstrip high-isolation radial power synthesizing amplifier, which comprises two broadband air microstrip high-isolation radial power distribution/synthesizers and at least one power amplifier module. The broadband air microstrip high isolation radial power divider/combiner includes an input waveguide, a coaxial transition structure between the input waveguide and the radial waveguide, a radial waveguide, a radial air microstrip line, and at least one output waveguide; The radial waveguide is connected to the input waveguide through a coaxial probe transition structure at its central position; air microstrip lines distributed radially are connected around the radial waveguide, and adjacent air microstrip lines are pasted with A thin-film resistor; each of the air microstrip lines is respectively connected to an output waveguide. The broadband air microstrip high-isolation radial power synthesizing amplifier of the present invention can realize power synthesizing with one-multiplexing, single-mode operation, broadband and high efficiency.

Description

Broadband Air Microstrip High Isolation Radial Power Combining Amplifier

technical field

The present invention relates to the power synthesis technology used in the microwave and millimeter wave frequency bands, in particular to the radial power of a broadband air microstrip structure with high isolation (the coupling coefficient between ports is less than -20dB and can be called high isolation) Synthetic amplifier.

Background technique

In the microwave high-end and millimeter wave frequency bands, with the increase of frequency, the size of semiconductor solid-state devices decreases, the power capacity decreases, and the output power of a single device is difficult to meet the needs of communication electronic systems. People have proposed the power synthesis of multiple solid-state devices. way to realize high-power solid-state power devices. The properties of the power combining network directly determine the properties of the combining amplifier. Therefore, the key to the power combining technology is the nature of the power combining network. The focus of the research is to explore which combining network topology can achieve the maximum efficiency of broadband and large number of power combining.

Among various power combining network topologies, the radial power splitter/combiner has always been the focus of people's attention, and various radial structures have been proposed and applied in power combining technologies. The origin of the radial power divider/combiner can be traced back to the N-way power splitter proposed by Wilkinson in the 1960s. Later, the power splitter was named after him and was widely used. A radial power splitter/combiner usually feeds an input signal into the center of a disk structure through a circularly symmetrical transmission line (like an axis), and then leads out multiple output ports around the disk structure. There are many forms of disc structures and output ports. Generally speaking, there are resonant structures and non-resonant structures. The former disc structure is a closed cavity, while the latter is an open structure.

The biggest advantage of the radial power distribution/combiner is that it can complete a large number of power distribution/combination at one time, and the insertion loss is basically not affected by the number of synthesis channels, so this structure is especially suitable for a large number of power synthesis amplifiers. At the same time, the structural symmetry of the radial power distribution/combiner ensures that the power distribution is consistent in amplitude and phase. In the millimeter wave band, the radial power distribution structure needs to ensure small insertion loss while suppressing high-order modes. The realization of these performances has been mentioned in some patents. For example, the patent US4673899 uses a pure waveguide structure to ensure small insertion loss, and at the same time slots on the surface of the radial waveguide to achieve high-order mode suppression; the patent US4926145 also adopts a waveguide structure. Both the axial and radial waveguide surfaces are grooved, and the surface of the grooves is covered with absorbing material to suppress high-order modes.

However, no radial power divider/combiner with matching and isolated output ports applicable to the mmWave band has been implemented in previous structures. The active device units in the middle of the port-matched and isolated power distribution/combiner are independent of each other, which can effectively avoid problems such as self-excitation of the synthesized amplifier. At the same time, the high-isolation divider will also make the failure characteristics of the synthetic amplifier good, that is, when an active device unit is damaged, the remaining units can still work normally, and the output power will only drop in a predictable ratio. Therefore, it is necessary to study a radial power combining amplifier that can be applied in the millimeter wave band and can realize multi-channel, broadband, and high-efficiency output port matching and isolation.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings and deficiencies in the prior art, and provides a broadband air microstrip high-isolation radial power synthesis amplifier. Radial Power Splitter/Combiner to achieve. The broadband air microstrip high-isolation radial power divider/combiner is used to realize multi-channel, broadband and high-efficiency power combining amplifiers in the millimeter wave high-end and microwave bands.

In order to achieve the above object, the present invention is achieved through the following technical solutions: a broadband air microstrip high isolation radial power synthesis amplifier, characterized in that: two broadband air microstrip high isolation radial power distribution/synthesizers and at least one power amplifier module; the broadband air microstrip high-isolation radial power distribution/combiner includes an input waveguide, a coaxial transition structure between the input waveguide and the radial waveguide, a radial waveguide, and a radial air microstrip line, and at least one output waveguide; the radial waveguide is connected to the input waveguide through a coaxial probe transition structure at its central position; the air microstrip lines distributed radially are connected around the radial waveguide, adjacent Thin-film resistors are pasted between the air microstrip lines; each of the air microstrip lines is connected to an output waveguide;

The two broadband air microstrip high-isolation radial power distribution/combiners and at least one power amplifier module are connected as follows: one of the broadband air microstrip high-isolation radial power distribution/combiners is used as a power divider, and the other Broadband air microstrip high-isolation radial power divider/combiner is used as a power combiner. The power combiner is consistent with the power divider in structure, and its application method is opposite to that of the power divider; the external input is connected to the power divider Each output waveguide of the power divider is connected to an input port of a power amplifier module, and the output port of the power amplifier module is correspondingly connected to an output waveguide of a power combiner, and the input waveguide of the power combiner is used as a broadband air micro Output port with high isolation radial power combining amplifier. Because the power combiner is opposite to the power splitter, each output waveguide of the power combiner in the above scheme is used as the input of the broadband air microstrip high-isolation radial power combiner.

Furthermore, the conduction band of the radial air microstrip line is formed by slotting on a flat conductor; the conduction band of the air microstrip line is radially enlarged.

The thin film resistor sheet covers the bottom of the conduction band of the air microstrip line; the thin film resistor sheet can effectively suppress high-order modes, and realize output matching and high isolation characteristics between output ports; the resistance of the thin film resistor sheet The value is determined by the odd-even mode method according to the output port matching and the high isolation characteristics between the ports. Assuming that the impedance of each output waveguide is Z ₀ , the initial value of the resistance Z of the thin film resistor can be determined according to the following formula Z=Z ₀ /2, due to the discontinuity of the field, the resistance value of the thin film resistor needs to be optimized.

A first matching transition structure is also included between the input waveguide and the radial waveguide, a second matching transition structure is also included between the radial waveguide and the radial air microstrip line, and a second matching transition structure is also included between the radial air microstrip line and the output waveguide. Including a third matching transition structure, the first, second, and third matching transition structures are used to realize broadband impedance matching, all of which are cavity structures, and the matching structure can be realized by one of the following matching structures: One impedance transformer, multi-section quarter impedance transformer, Chebyshev impedance transformer and tapered transmission line.

The broadband air microstrip high-isolation radial power distribution/combiner is an all-waveguide structure.

Both the input and output ports of the power divider and the power combiner are waveguide ports.

The operating principle of the broadband air microstrip high isolation radial power distribution/synthesizer in the broadband air microstrip high isolation radial power synthesis amplifier provided by the present invention is as follows: when the microwave signal enters the input waveguide, it passes through the waveguide-coaxial converter The signal is transmitted to the coaxial line whose field distribution is circular symmetry, the coaxial line feeds the signal at the center of the radial waveguide, the signal propagates along the radial direction in the radial waveguide, and is fed into the air microstrip line, and finally transmitted to the rectangular waveguide output. In order to achieve broadband matching characteristics, the first, second, and third matching are designed between the input waveguide and the radial waveguide, between the radial waveguide and the radial microstrip line, and between the radial air microstrip line and the output waveguide. transition structure. A thin-film resistor is set at the bottom of the conduction band of the radial air microstrip line, which is used to achieve the matching between the output ports and the isolation characteristics between the ports, and at the same time absorb some high-order modes, that is, the mode in which the current direction is transverse, effectively suppressing high order mode.

The broadband air microstrip high-isolation radial power combining amplifier of the present invention is a power combining amplifier formed by the above-mentioned wide-band air microstrip high-isolation radial power distribution/combiner. The power combining amplifier includes a power divider, at least one power amplification module and a power combiner. The structural forms of the power divider and the power combiner are broadband air microstrip high-isolation radial power dividers, and the power combiner is just the reverse application of the power divider. The power combiner and the power divider are mirror-symmetrical up and down. The power amplifying module is located between the power divider and the power combiner, the input port of the power amplifying module is connected to the output port of the power divider, and the output port is connected to the input port of the power combiner. The form of the power amplifier module is not fixed, it only needs to meet the above port requirements. The power amplifying module is a waveguide port, and other high-performance power combining structures can be combined at this time, for example, a coupler structure or a magic T structure can be combined in the power amplifying module.

Compared with the prior art, the present invention has the following advantages:

1. The broadband air microstrip high-isolation radial power divider/combiner contained in the broadband power combining amplifier provided by the present invention can realize power distribution/combining of one-point multi-channel, single-mode operation, broadband, low loss, and high isolation .

2. The broadband air microstrip high isolation radial power synthesis amplifier provided by the present invention, its power distribution/combiner can effectively suppress high sub-mode to achieve very good output matching and high isolation between output ports. By suppressing higher-order modes, this structure can realize arbitrary power distribution/combination.

3. In the broadband air microstrip high-isolation radial power combining amplifier provided by the present invention, its power distribution/combining device realizes the characteristics of broadband operation by designing multiple impedance matching transition structures.

4. The broadband air microstrip high-isolation radial power synthesis amplifier provided by the present invention has a power distribution/combiner with a full waveguide structure, no dielectric loss, and only a very low conductor loss. Therefore, the power distribution/combiner constituted The power combining amplifier has the characteristics of high power combining efficiency.

5. The broadband air microstrip high-isolation radial power combining amplifier provided by the present invention has the input/output port form of the power distribution/combiner as a waveguide port. This structure is very easy to combine with other high-performance power combining structures, such as coupling device structure, magic T structure, etc. The power amplifier module can be made separately, which is convenient for processing and debugging.

6. The broadband power combining amplifier provided by the present invention is composed of two broadband air microstrip high-isolation radial power distribution/combining devices and at least one power amplification module. The wide-band air microstrip high-isolation radial power combining amplifier can realize power combining of one-multiplexing, single-mode operation, broadband and high efficiency.

Description of drawings

Fig. 1 is the structural diagram of an embodiment of broadband air microstrip high isolation radial power division synthesizing amplifier in the present invention;

Fig. 2 is a top view of the separation structure of the power distribution/combiner in Fig. 1;

Fig. 3 is a partial diagram of part A in Fig. 2;

Fig. 4 is a partial diagram of part B in Fig. 2;

Fig. 5 is a schematic diagram of the power distribution/combiner in Fig. 1;

FIG. 6 is a structural diagram of the power amplification module 6 in FIG. 1 .

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. However, the embodiments of the present invention are not limited thereto.

Example

A 36-way broadband air microstrip high-isolation radial power synthesis amplifier is taken as an example for illustration below.

The overall structure of the 36-way broadband air microstrip high-isolation radial power combining amplifier is shown in Figure 1. The structure includes a power divider 8, multiple power amplification modules 6, and a power combiner 9. The structure of the power combiner is the same as that of the power divider, and the power combiner just applies the power divider in reverse. The power combiner and the power divider are mirror-symmetrical up and down. The power amplifying module 6 is located between the power divider 8 and the power combiner 9 , its input port is connected to the output port 41 of the power divider 8 , and the output port is connected to the input port 41 of the power combiner 9 . The input and output ports of the power divider 8 and the power combiner 9 are waveguide ports. The form of the power amplifying module 6 is not fixed, it only needs to meet the above requirements of the waveguide port.

Figure 2 shows the top view of the broadband air microstrip high isolation radial power distribution/combiner separation structure. The power splitter/combiner consists of two major parts, the top-level structure 1 and the bottom-level structure 2 . The top layer structure 1 and the bottom layer structure 2 are closely combined to form the input waveguide 11, the radial waveguide 21, the coaxial transition structure 51 between the input waveguide 11 and the radial waveguide 21, the air microstrip line 31, the output waveguide 41, and the air Cavity structures such as the transition structure 412 between the microstrip line 31 and the output waveguide 41 .

The power divider is a waveguide structure. In this way, the structure is not filled with any medium, only the conductor loss, which can obtain good low loss characteristics. On the surface of the top structure 1 , a part of the conductor is cut out to form the cavity of the input waveguide 11 . On the side of the top structure 1 facing the bottom structure 2, there is a flat conductor plane with a hole in the center for inserting a coaxial probe. In the very center of the underlying structure 2 there is a coaxial transition structure 51 between the input waveguide 11 and the radial waveguide 21 . The coaxial transition structure 51 is surrounded by a conductor plane, which forms the radial waveguide 21 together with the top plane. Wherein, the radius of the radial waveguide 21 should not be too large, and it only needs to satisfy the condition of single-mode operation. An air microstrip line 31 is connected around the radial waveguide 21 , and the conduction band of the air microstrip line is a structure 312 . The conduction band 312 of the air microstrip line is formed by slotting a flat conductor on the underlying structure 2 . The conduction strip 312 of the air microstrip line exhibits a radially enlarged shape. At the bottom of the groove 312, a thin film resistor 313 is covered. The air microstrip line 31 is connected to the output waveguide 41 through a short waveguide 412 with enlarged broadside, and the waveguide 412 with enlarged broadside realizes the function of impedance matching. The main cavity of the output waveguide 41 is formed by digging out a cavity in the bottom structure 2 .

FIG. 3 is a partial diagram of part A in FIG. 2 , from which the specific structure of the input waveguide 11 can be seen. The vertically propagating input waveguide 111 is transformed into a horizontally propagating waveguide 113 by a cut-off structure 112 . In the waveguide 113 there is a transition to the radial waveguide 21 through the coaxial probe structure 51 . The cavity structure of the coaxial probe is realized through the opening 114 .

FIG. 4 is a partial view of part B in FIG. 2 , from which the specific structure of the coaxial probe transition structure 51 can be seen. The coaxial probe transition structure 51 is formed by connecting three conductor cylinders with different radii. The uppermost one is 511 , which will go through the hole 114 deep into the horizontal waveguide 113 . A conductor cylinder 512 with a larger radius is connected to the bottom of the 511, and then a conductor cylinder 513 with a larger radius is connected. Good impedance matching between the input waveguide 11 and the radial waveguide 21 can be achieved by these conductor cylinders.

FIG. 5 further provides a schematic circuit diagram of the power distribution/combiner, which can help to understand this embodiment. The air microstrip line 31 in this embodiment can also be replaced with a double-sided parallel strip line, which only needs to be slotted on the top layer structure 1 facing the slot of the bottom structure 2, and the thin film resistor sheet 313 can cover to two layers of grooved surface.

FIG. 6 shows a structural diagram of the power amplifying module 6 in FIG. 1 , which shows a dual-probe spatial power combining structure. The power amplification module 6 is divided into two parts, an upper layer 61 and a lower layer 62 . The basic working process of the amplification module is to input signal power through a waveguide 71, then couple to the microstrip through the planar probe 72, and then connect to the amplifier 73, and finally the power output by the amplifier is coupled to the output waveguide through the microstrip probe. The microstrip probe 72 and the amplifier unit 73 in the amplifying module both exist on the bottom layer and the top layer, which is actually a two-way spatial power combining structure. All the amplifier chips in Figure 8 are welded to the bottom layer or the bottom metal cavity, which can achieve good heat dissipation. The top and bottom surfaces can be designed as sheet-like heat dissipation structures, which can be blackened to further improve heat dissipation, and fans can also be used for forced heat dissipation.

The above-mentioned embodiment is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited by the above-mentioned embodiment, and any other changes, modifications, substitutions, combinations, Simplifications should be equivalent replacement methods, and all are included in the protection scope of the present invention.

Claims (7)

1. a broadband air microstrip height is isolated radially power synthesis amplifier, it is characterized in that: isolating radially by two broadband air microstrip height, power division/synthesizer constitutes with at least one power amplifier module;

Said broadband air microstrip height isolates radially that power division/synthesizer comprises coaxial transition structure, radial waveguide, radial air microstrip line between input waveguide, input waveguide and the radial waveguide, and at least one output waveguide; Said radial waveguide heart position therein is connected with input waveguide through the coaxial probe transition structure; Be connected with radially-arranged air microstrip line around the said radial waveguide, post the film resistor sheet between the adjacent air microstrip line; Said every air microstrip line connects an output waveguide respectively;

Said broadband air microstrip height is isolated radially, and power division/synthesizer is connected with at least one power amplifier module as follows: one of them broadband air microstrip height is isolated radially power division/synthesizer as power divider; Another broadband air microstrip height is isolated radially power division/synthesizer as power combiner; Said power combiner is consistent with power divider on version, and its application mode and power divider are opposite; Outside input connects the input waveguide of said power divider; Each output waveguide of said power divider connects the input port of a power amplifier module; The corresponding output waveguide that connects power combiner of the delivery outlet of this power amplifier module, the input waveguide of power combiner is isolated the radially delivery outlet of power synthesis amplifier as broadband air microstrip height.

2. broadband according to claim 1 air microstrip height is isolated radially power synthesis amplifier, it is characterized in that: the generation type of the conduction band of said radial air microstrip line is that the mode with fluting forms on smooth conductor; The conduction band of air microstrip line is radially enlarged shape.

3. broadband according to claim 2 air microstrip height is isolated radially power synthesis amplifier, it is characterized in that: the film resistor sheet covers the bottom of said air microstrip line conduction band.

4. broadband according to claim 3 air microstrip height is isolated radially power synthesis amplifier; It is characterized in that: said film resistor sheet is that the side at a dielectric substrate plates film resistor and forms, and the resistance of said film resistor sheet is confirmed according to the high isolation characteristic between output port coupling and the port by the odd even modulus method.

5. broadband according to claim 1 air microstrip height is isolated radially power synthesis amplifier, it is characterized in that: also comprise between said input waveguide and the radial waveguide also comprising between the first matching transition structure, radial waveguide and the radial air microstrip line and also comprising the 3rd matching transition structure between the second matching transition structure, radial air microstrip line and the output waveguide; Said first, second is used to realize wideband impedance match with the 3rd matching transition structure, is cavity body structure; Said matching structure is realized with a joint above 1/4th impedance transformers or gradual change impedance matching box.

6. broadband according to claim 1 air microstrip height is isolated radially power synthesis amplifier, it is characterized in that: said broadband air microstrip height isolates radially that power division/synthesizer is the all-wave guide structure.

7. broadband according to claim 1 air microstrip height is isolated radially power synthesis amplifier, and it is characterized in that: the input/output end port of said power divider and power combiner is waveguide port.

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