Radio frequency power amplifier integrated antenna

Abstract

The invention discloses a radio frequency power amplifier integrated antenna, which comprises an input matching network of a power amplifier, a power amplification transistor connected with the input matching network, and a wide slot antenna unit directly connected with the output end of the power amplification transistor, the wide slot antenna unit comprises a feeder line, a radiation main body and at least one group of harmonic tuning components, and a wide slot is formed in the radiation main body and is used for realizing fundamental wave matching of the power amplifier; the harmonic tuning component comprises a plurality of loading branches and is used for tuning the harmonic impedance of the power amplifier; the plurality of loading branches extend from the edge of the wide groove to the interior of the wide groove and are symmetrically distributed on the two sides of the feeder line. According to the invention, accurate harmonic impedance modulation can be realized in a wider frequency range, the harmonic component of the power amplification crystal is superposed on the fundamental wave, and the harmonic power of the power amplifier is converted into useful power, so that the overall efficiency of the power amplifier integrated antenna is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of antennas, and in particular relates to a radio frequency power amplifier integrated antenna. Background Art

[0002] With the rapid development of wireless communication technology, the demand for high-efficiency RF front-end equipment is increasing. As a crucial component in wireless communication systems, the performance of power amplifiers (PAs) directly affects the energy efficiency and communication quality of the entire system. However, traditional PAs and antennas are usually designed and optimized as independent components. This design method inevitably brings about problems such as large size, high loss, and high complexity, which is not conducive to achieving miniaturization and high performance of wireless communication equipment.

[0003] In traditional designs, a complex output matching network (OMN) is required between the PA output and the antenna input. These networks introduce additional losses and reduce the efficiency of the system. In order to improve the efficiency of the system, the existing PA integrated antenna design can directly match the output impedance of the antenna and the transistor, and remove the matching network between the PA and the antenna to improve the efficiency of the system. However, the PA antenna integration solution in the prior art still cannot meet the efficiency requirements of the system. Summary of the invention

[0004] In order to solve the above problems existing in the prior art, the present invention provides a radio frequency power amplifier integrated antenna. The technical problem to be solved by the present invention is achieved by the following technical solutions:

[0005] The present invention provides a radio frequency power amplifier integrated antenna, comprising an input matching network of a power amplifier, a power amplifier transistor connected to the input matching network, and a wide slot antenna unit directly connected to the output end of the power amplifier transistor, wherein:

[0006] The wide slot antenna unit includes a feed line, a radiating body and at least one group of harmonic tuning components. A wide slot is opened inside the radiating body for achieving fundamental wave matching of the power amplifier; the harmonic tuning component includes a plurality of loading branches for tuning the harmonic impedance of the power amplifier; the plurality of loading branches extend from the edge of the wide slot to the inside of the wide slot and are symmetrically distributed on both sides of the feed line.

[0007] In one embodiment of the present invention, the radiation body is a metal frame arranged on the front side of the substrate of the wide slot antenna unit, the wide slot is opened inside the metal frame, the feeder is arranged on the back side of the substrate, and the feeder is perpendicular to the first outer edge of the metal frame;

[0008] The multiple loading branches in the harmonic tuning component are parallel to the feed line, and extend from a first edge of the wide slot and a second edge opposite to the first edge toward the inside of the wide slot respectively. The first edge and the second edge of the wide slot are perpendicular to the feed line.

[0009] In one embodiment of the present invention, each group of harmonic tuning components includes four loading branches of the same size, namely, a first branch, a second branch, a third branch and a fourth branch;

[0010] The first branch node and the third branch node both extend from the first edge of the wide groove toward the inside of the wide groove and are perpendicular to the first edge of the wide groove;

[0011] The second branch node and the fourth branch node both extend from the second edge of the wide groove toward the inside of the wide groove and are perpendicular to the second edge of the wide groove;

[0012] The first branch and the second branch are arranged on the same straight line, located on the first side of the feeder and spaced apart from each other; the third branch and the fourth branch are arranged on the same straight line, located on the second side of the feeder and spaced apart from each other.

[0013] In one embodiment of the present invention, the wide slot further includes a third edge and a fourth edge perpendicular to the first edge and the second edge, the third edge is located on the first side of the feeder, and the fourth edge is located on the second side of the feeder;

[0014] The distance between each of the loading branches and the third edge or the fourth edge is related to the operating frequency of the radio frequency power amplifier integrated antenna.

[0015] In one embodiment of the present invention, the interval W between the third edge and the fourth edge of the wide groove is f Determined by a quarter wavelength corresponding to the operating frequency of the radio frequency power amplifier integrated antenna;

[0016] The distance between the lower edge of the first branch node and the lower edge of the second branch node and the third edge is W. f (n-1) / 2n; the distance between the upper edge of the third branch and the upper edge of the fourth branch and the fourth edge is W f (n-1) / 2n;

[0017] Among them, n represents the harmonic tuning component used to tune the nth harmonic impedance of the power amplifier; the lower edge is the side of the first branch or the third branch away from the third edge; the upper edge is the side of the second branch or the fourth branch away from the fourth edge.

[0018] In one embodiment of the present invention, the at least one group of harmonic tuning components includes a second harmonic tuning component and a third harmonic tuning component, wherein:

[0019] The second harmonic tuning component is used to tune the impedance of the second harmonic of the power amplifier; the third harmonic tuning component is used to tune the impedance of the third harmonic of the power amplifier.

[0020] In one embodiment of the present invention, the impedance of the second harmonic or the impedance of the third harmonic is related to the size parameters of the loading branch; the size parameters include at least one of the shape, length, width of the loading branch and the distance between different loading branches.

[0021] In one embodiment of the present invention, tuning the harmonic impedance of the power amplifier includes tuning the harmonic impedance of the power amplifier to an open circuit state or a short circuit state; the impedance state of the harmonic impedance is related to the working type of the power amplifier.

[0022] In one embodiment of the present invention, when the power amplifier operates in a Class F operating state, the at least one set of harmonic tuning components is used to tune the second harmonic impedance of the power amplifier to a short-circuit state and tune the third harmonic impedance of the power amplifier to an open-circuit state;

[0023] When the power amplifier operates in an inverse class F operating state, the at least one set of harmonic tuning components is used to tune the second harmonic impedance of the power amplifier to an open circuit state and tune the third harmonic impedance of the power amplifier to a short circuit state.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The present invention proposes a radio frequency power amplifier integrated antenna, including an input matching network of a power amplifier, a transistor and a wide slot antenna unit, wherein the input impedance of the wide slot antenna unit is used to match the output impedance of the PA, and multiple equivalent capacitor and inductor resonant networks are introduced through its multi-loading branch structure, and the high-order harmonic impedance of the PA can be adjusted by adjusting the number, length, width and shape of these loading branches (adjusting the number and size of equivalent capacitors and inductors), so that the harmonic impedance of the power amplifier is located at a preset open circuit point or short circuit point, so that the harmonic power of the PA is superimposed on the fundamental wave, and it is effectively converted into useful power instead of being wasted. This energy recovery and reuse can improve the overall efficiency of the PA integrated antenna.

[0026] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of a radio frequency power amplifier integrated antenna provided by an embodiment of the present invention;

[0028] Figure 2 is a structural schematic diagram of a wide slot antenna unit provided by an embodiment of the present invention;

[0029] Figure 3 is a schematic structural diagram of a wide slot provided by an embodiment of the present invention;

[0030] Figure 4 is a structural schematic diagram of another wide slot antenna unit provided by an embodiment of the present invention;

[0031] Figure 5 1 is a schematic diagram of an equivalent circuit of a wide slot antenna unit provided by an embodiment of the present invention;

[0032] Figure 6 is a circuit structure diagram of a design example of a radio frequency power amplifier integrated antenna provided by an embodiment of the present invention;

[0033] Figure 7 is a structural diagram of an input matching network provided by an embodiment of the present invention;

[0034] Figure 8 is a structural diagram of a wide slot antenna unit provided by an embodiment of the present invention;

[0035] Fig. 9 It is a current and voltage waveform diagram of a transistor current source end face of a radio frequency power amplifier integrated antenna provided by an embodiment of the present invention;

[0036] Fig.10 It is a test result diagram of output power, power added efficiency and equivalent isotropic radiated power of a radio frequency power amplifier integrated antenna provided in an embodiment of the present invention at 3.3-3.8 GHz;

[0037] Fig.11 The invention provides an E-plane, H-plane fundamental wave and harmonic frequency radiation pattern of a radio frequency power amplifier integrated antenna. DETAILED DESCRIPTION

[0038] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, a radio frequency power amplifier integrated antenna proposed according to the present invention is described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0039] The above and other technical contents, features and effects of the present invention are clearly presented in the following detailed description of the specific implementation modes in conjunction with the accompanying drawings. Through the description of the specific implementation modes, the technical means and effects adopted by the present invention to achieve the predetermined purpose can be more deeply and specifically understood. However, the attached drawings are only for reference and explanation purposes and are not used to limit the technical solutions of the present invention.

[0040] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants are intended to cover non-exclusive inclusion, so that an article or device including a series of elements includes not only those elements, but also other elements that are not explicitly listed. In the absence of more restrictions, the elements defined by the statement "including one..." do not exclude the existence of other identical elements in the article or device including the elements.

[0041] Embodiment 1

[0042] See also Figure 1 and Figure 2 , Figure 1 is a module schematic diagram of a radio frequency power amplifier integrated antenna provided by an embodiment of the present invention, Figure 2 It is a structural schematic diagram of a wide slot antenna unit provided by an embodiment of the present invention. The RF power amplifier integrates an input matching network of an antenna power amplifier, a power amplifier transistor connected to the input matching network, and a wide slot antenna unit directly connected to the output end of the power amplifier transistor, wherein the input matching network is used to transmit RF signals so that the RF signals are transmitted to the gate of the transistor with low loss and integrity; the transistor is used to amplify the RF signal input to the gate of the transistor, and output the RF signal from the drain of the transistor to the wide slot antenna unit; the wide slot antenna unit includes a feeder, a radiating body, and at least one group of harmonic tuning components, wherein a wide slot is provided inside the radiating body for achieving fundamental wave matching of the power amplifier; the harmonic tuning component includes a plurality of loading branches for tuning the harmonic impedance of the power amplifier; the plurality of loading branches extend from the edge of the wide slot to the inside of the wide slot, and are symmetrically distributed on both sides of the feeder.

[0043] For further information, see Figure 3 , Figure 3 The schematic diagram of the structure of a wide slot provided by an embodiment of the present invention is shown in FIG. The radiating body of the present embodiment is a metal square frame arranged on the front of the substrate of the wide slot antenna unit, a wide slot is opened inside the metal square frame, a feed line is arranged on the back of the substrate, and the feed line is perpendicular to the first outer edge of the metal square frame.

[0044] The harmonic tuning component includes a plurality of loading branches, which are parallel to the feeder and extend from a first edge of the wide slot and a second edge opposite to the first edge to the inside of the wide slot, respectively. The first edge and the second edge of the wide slot are perpendicular to the feeder, such as Figure 2 shown.

[0045] In practice, the multiple loading branches are used to realize the secondary and higher harmonic modulation of the power amplifier; the drain of the power amplifier transistor is directly connected to the wide slot antenna unit, and the input impedance of the wide slot antenna unit can be matched to the maximum efficiency impedance point or the maximum power impedance point or the intermediate impedance point between the maximum efficiency impedance point and the maximum power impedance point of the power amplifier transistor by changing the size of the feed line and the wide slot in the wide slot antenna unit; harmonic matching is performed by changing the length, width, number and shape of the loading branches, so that the secondary and higher harmonic components of the power amplifier transistor can be in an open circuit / short circuit state. For a class F harmonic modulation amplifier, it is necessary to modulate the second harmonic impedance of the power amplifier transistor to a short circuit point, and the third harmonic impedance to an open circuit point. For an inverse class F harmonic modulation amplifier, it is necessary to modulate the second harmonic impedance of the power amplifier transistor to an open circuit point, and the third harmonic impedance to a short circuit point, so that the harmonic components of the power amplifier transistor are superimposed on the fundamental wave.

[0046] The RF power amplifier integrated antenna of this embodiment directly connects the output port of the power amplifier transistor to the wide slot antenna unit, and matches the input impedance of the wide slot antenna unit to the maximum efficiency impedance point or the maximum power impedance point or the intermediate impedance point of the power amplifier transistor; and, by adjusting the length, width, number and shape of the loaded branches in the wide slot antenna unit, harmonic matching is performed, so that the secondary and higher harmonic components of the power amplifier transistor are in an open circuit / short circuit state, so that the harmonic components of the transistor are superimposed on the fundamental wave, thereby improving the output power and efficiency of the PA.

[0047] The power amplifier transistor of this embodiment can be a GaN HEMT device, MOSFET, BJT, HBT or other triode or field effect transistor device. The gate of the power amplifier transistor is connected to the input matching network, and the drain is connected to the feeder of the wide slot antenna unit.

[0048] The number of loading branches set in the wide slot antenna unit is related to the harmonic order. The higher the harmonic order to be tuned, the more loading branches are set in the wide slot antenna unit. If the harmonic order to be tuned is n, the number of loading branches set in the wide slot antenna unit is 4n-4, where 2≤n≤5. The shape of the loading branch can be square or trapezoidal, depending on the operating frequency of the power amplifier and the harmonic impedance value that needs to be modulated for the power amplifier.

[0049] In this embodiment, each group of harmonic tuning components includes four loading branches of the same size, namely the first branch, the second branch, the third branch and the fourth branch, wherein the first branch and the third branch both extend from the first edge of the wide slot to the inside of the wide slot and are perpendicular to the first edge of the wide slot; the second branch and the fourth branch both extend from the second edge of the wide slot to the inside of the wide slot and are perpendicular to the second edge of the wide slot; the first branch and the second branch are arranged on the same straight line, located on the first side of the feeder and spaced from each other; the third branch and the fourth branch are arranged on the same straight line, located on the second side of the feeder and spaced from each other.

[0050] The wide slot of this embodiment also includes a third edge and a fourth edge perpendicular to the first edge and the second edge, the third edge is located on the first side of the feeder line, and the fourth edge is located on the second side of the feeder line; the spacing between each loading branch and the third edge or the fourth edge is related to the operating frequency of the RF power amplifier integrated antenna.

[0051] Furthermore, the interval W between the third edge and the fourth edge of the wide groove is f Determined by the quarter wavelength corresponding to the operating frequency of the RF power amplifier integrated antenna; the distance between the lower edge of the first branch and the lower edge of the second branch and the third edge is W f (n-1) / 2n; the distance between the upper edge of the third branch and the upper edge of the fourth branch and the fourth edge is W f (n-1) / 2n; wherein n represents the harmonic tuning component used to tune the nth harmonic impedance of the power amplifier; the lower edge is the side of the first branch or the second branch away from the third edge; the upper edge is the side of the third branch or the fourth branch away from the fourth edge.

[0052] The at least one group of harmonic tuning components includes a second harmonic tuning component and a third harmonic tuning component, wherein the second harmonic tuning component is used to tune the impedance of the second harmonic of the power amplifier; the third harmonic tuning component is used to tune the impedance of the third harmonic of the power amplifier. The harmonic impedance is related to the size parameters of the loading branches; the size parameters include at least one of the shape, length, width of the loading branches and the distance between different loading branches.

[0053] Tuning the harmonic impedance of the power amplifier includes tuning the harmonic impedance of the power amplifier to an open circuit state or a short circuit state; the impedance state of the harmonic impedance is related to the working type of the power amplifier.

[0054] When the power amplifier operates in a Class F operating state, at least one group of harmonic tuning components is used to tune the second harmonic impedance of the power amplifier to a short-circuit state, and to tune the third harmonic impedance of the power amplifier to an open-circuit state; when the power amplifier operates in a reverse Class F operating state, at least one group of harmonic tuning components is used to tune the second harmonic impedance of the power amplifier to an open-circuit state, and to tune the third harmonic impedance of the power amplifier to a short-circuit state.

[0055] Embodiment 2

[0056] Based on the first embodiment, this embodiment provides another schematic diagram of the structure of a wide slot antenna unit, see Figure 4 , Figure 4 The number of loaded branches in the antenna is 4. In actual design, the number and size of loaded branches can be determined according to the type of harmonic modulation PA and the order of harmonic modulation. By adjusting the size and number of loaded branches in the antenna, the secondary and higher harmonic modulation of various harmonic modulation PAs can be realized, which significantly improves the efficiency of PA integrated antenna.

[0057] When the second harmonic impedance of the power amplifier needs to be modulated, the at least one group of harmonic tuning components includes a second harmonic tuning component, which includes a first loading branch extending from the edge of the wide slot to the middle of the wide slot (corresponding to Figure 4 Branch 1 in), the second loading branch (corresponding to Figure 4 Node 2 in the third loading node (corresponding to Figure 4 Branch 3) and the fourth loading branch (corresponding to Figure 4 The first loading branch and the third loading branch extend from the first edge of the wide slot to the middle of the wide slot respectively; the second loading branch and the fourth loading branch extend from the second edge of the wide slot opposite to the first edge to the middle of the wide slot respectively; the feed line extends vertically from the center of the first outer edge of the radiation body to the vertical upper side of the wide slot between the first loading branch and the third loading branch, the first loading branch and the second loading branch are located on the first side of the feed line, and the third loading branch and the fourth loading branch are located on the second side of the feed line. The second harmonic tuning component is used to tune the impedance of the second harmonic of the power amplifier.

[0058] In a specific embodiment, the first loading branch and the third loading branch are located on the same straight line perpendicular to the first edge of the wide groove and are not connected to each other; the second loading branch and the fourth loading branch are located on the same straight line perpendicular to the first edge of the wide groove and are not connected to each other.

[0059] As described above, the distance between the lower edge of the first branch and the lower edge of the second branch and the third edge is W. f (n-1) / 2n; the distance between the upper edge of the third branch and the upper edge of the fourth branch and the fourth edge is Wf (n-1) / 2n; where n represents the harmonic tuning component used to tune the nth harmonic impedance of the power amplifier. In this embodiment, the first loading branch, the second loading branch, the third loading branch and the fourth loading branch are used to tune the 2nd harmonic impedance of the power amplifier. Therefore, n=2, and the distance between the lower edge of the first branch and the lower edge of the second branch and the third edge is W. f / 4; the distance between the upper edge of the third branch and the upper edge of the fourth branch and the fourth edge is W f / 4.

[0060] Embodiment 3

[0061] Based on the above embodiment, this embodiment provides another structural diagram of a wide slot antenna unit, such as Figure 2 As shown, when the second and third harmonics of the power amplifier need to be adjusted, the wide slot of the wide slot antenna unit is provided with a first loading branch extending toward the inside of the wide slot (corresponding to Figure 2 Branch 1 in), the second loading branch (corresponding to Figure 2 Node 2 in the third loading node (corresponding to Figure 2 Branch 3 in), the fourth loading branch (corresponding to Figure 2 4), the fifth loading branch (corresponding to Figure 2 The branch 5 in the sixth loading branch (corresponding to Figure 2 6), the seventh loading branch (corresponding to Figure 2 The branch 7) and the eighth loading branch (corresponding to Figure 2 The branches in the 8).

[0062] In a specific embodiment, the first loading branch, the third loading branch, the fifth loading branch and the seventh loading branch extend from the first edge of the wide slot to the middle of the wide slot respectively; the second loading branch, the fourth loading branch, the sixth loading branch and the eighth loading branch extend from the second edge of the wide slot opposite to the first edge to the middle of the wide slot respectively; the first loading branch, the second loading branch, the fifth loading branch and the sixth loading branch are located on the first side of the feeder, and the third loading branch, the fourth loading branch, the seventh loading branch and the eighth loading branch are located on the second side of the feeder.

[0063] Preferably, the first loading branch and the second loading branch are located on the same straight line perpendicular to the first edge of the wide groove and are not connected to each other; the third loading branch and the fourth loading branch are located on the same straight line perpendicular to the first edge of the wide groove and are not connected to each other; the fifth loading branch and the sixth loading branch are located on the same straight line perpendicular to the first edge of the wide groove and are not connected to each other; the seventh loading branch and the eighth loading branch are located on the same straight line perpendicular to the first edge of the wide groove and are not connected to each other.

[0064] In this embodiment, the first loading branch, the second loading branch, the third loading branch and the fourth loading branch are used to tune the second harmonic impedance of the power amplifier, and the fifth loading branch, the sixth loading branch, the seventh loading branch and the eighth loading branch are used to tune the third harmonic impedance of the power amplifier. Therefore, the distance between the lower edge of the fifth branch and the lower edge of the sixth branch and the third edge is W. f (n-1) / 2n=W f / 3; the distance between the upper edge of the seventh branch and the upper edge of the eighth branch and the fourth edge is W f / 3.

[0065] The implementation process of the radio frequency power amplifier integrated antenna of this embodiment includes:

[0066] First, the fundamental input impedance of the wide slot antenna unit to be designed is directly matched to the fundamental output impedance of the transistor. Figure 2 The feed line and the length and width of the wide slot in the antenna shown can achieve direct matching of the input impedance of the wide slot antenna unit to the impedance of the transistor. Specifically, the output impedance of the transistor refers to the impedance of the drain port of the power amplifier transistor. The gate of the power amplifier transistor inputs the RF signal, and the drain outputs the RF signal. Therefore, the impedance of the drain port of the power amplifier transistor is also called the output impedance. The drain of the power amplifier transistor is connected to the designed wide slot antenna unit. The signal needs to be transmitted from the drain of the power amplifier transistor to the wide slot antenna unit. The input impedance of the wide slot antenna unit needs to be matched with the output impedance of the power amplifier transistor, so that energy will not leak or be reflected back.

[0067] The number of loading branches in the wide slot antenna unit is determined according to the order of the PA harmonics to be modulated. Loading branches 1, 2, 3, and 4 are located 1 / 4 of the wide slot length (W f / 4) position, corresponding to the second harmonic impedance of the antenna, changing the size and shape of the corresponding branch node to change the second harmonic input impedance of the antenna, thereby modulating the second harmonic of the transistor; branches 5, 6, 7, 8 are located 1 / 3 of the wide slot length (W f / 3) corresponds to the third harmonic impedance of the antenna. Changing the size and shape of the corresponding branch changes the third harmonic input impedance of the antenna, thereby modulating the third harmonic of the transistor.

[0068] Multiple loading branches introduce multiple resonant networks for modulating transistor harmonic impedance, providing greater flexibility in harmonic modulation compared to existing PA integrated active antennas. Therefore, it can achieve accurate harmonic impedance modulation over a wider frequency range, thereby improving the efficiency of PA integrated active antennas over a wider spectrum. If only the 2nd harmonic of the PA needs to be adjusted, then only 4 loading branches are required, for example Figure 2The loading branches 1, 2, 3, and 4 in the antenna can be changed by changing the length and width of these loading branches to modulate the second harmonic impedance of the PA in the RF power amplifier integrated antenna, so that the second harmonic power of the PA is superimposed on the fundamental wave and effectively converted into useful power. If the second and third harmonics of the PA need to be adjusted, the number of loading branches needs to be 8, for example Figure 2 The loading branches 1, 2, 3, 4, 5, 6, 7, and 8 in the antenna can be changed. Changing the length and width of the loading branches 1, 2, 3, and 4 can modulate the secondary impedance of the PA in the RF power amplifier integrated antenna. Changing the length and width of the loading branches 5, 6, 7, and 8 can modulate the third harmonic impedance of the PA in the RF power amplifier integrated antenna, so that the output second harmonic and third harmonic of the PA are superimposed on the fundamental wave, effectively converting it into useful power. Similarly, the number of loading branches required for the 4th harmonic and the 5th harmonic is greater.

[0069] When the output port of the power amplifier transistor is directly connected to the wide slot antenna unit and the fundamental impedance of the power amplifier transistor has matched the input impedance of the antenna, multiple loading branches contained in the wide slot antenna unit are adjusted to realize transistor harmonic impedance modulation. The second harmonic impedance of the power amplifier can be modulated by adjusting the first loading branch, the second loading branch, the third loading branch and the fourth loading branch. The second harmonic impedance value of the power amplifier is modulated to an open circuit point or a short circuit point to realize harmonic energy recovery and improve the fundamental output power and efficiency of the power amplifier. The loading branch node, the sixth loading branch node, the seventh loading branch node and the eighth loading branch node can modulate the third harmonic impedance of the power amplifier, modulate the third harmonic impedance value of the power amplifier to an open circuit point or a short circuit point, realize the recovery of harmonic energy, and improve the fundamental output power and efficiency of the power amplifier; if higher-order harmonics such as the fourth harmonic need to be modulated, a loading branch node can be added above the seventh loading branch node and the eighth loading branch node (on the side close to the feeder line) and below the fifth loading branch node and the sixth loading branch node (on the side close to the feeder line) to realize the modulation of the fourth impedance of the power amplifier.

[0070] For further information, see Figure 5 , Figure 5 It is a schematic diagram of an equivalent circuit of a wide slot antenna unit provided by an embodiment of the present invention. As shown in the figure, the two loading branches in the wide slot antenna unit of this embodiment can be equivalent to two parallel series resonators (4L1-C1 / 4 and 4L2-C2 / 4). The loading branches in the left figure are rotationally symmetric, so the four groups of loading branches can be equivalent to two parallel series resonators (L1-C1 and L2-C2) in the right figure. If the number of modulations needs to be increased, such as four times, four more loading branches are added to the wide slot, and then the equivalent resonator L3-C3 in series is added in the red box area in the right figure. The equivalent input admittance Ys of the wide slot in the antenna can be expressed as:

[0071]

[0072] Among them, G s represents the radiation conductivity, B S represents the radiation susceptance, j represents the imaginary part, and ω represents the angular frequency.

[0073] The coupling between the feeder and the wide slot can be equivalent to a transformer with a turns ratio of k. The input impedance of the wide slot is Z l It can be expressed as:

[0074]

[0075] The input impedance of the antenna feeder (Zstub) can be expressed as:

[0076]

[0077] Among them, G m represents the conductance caused by the radiation from the open-circuit point of the feeder, B m G represents the susceptance caused by the radiation at the open point of the feeder. m and B m It is introduced by the open circuit point of the antenna feed line. m and λ m represents the characteristic impedance and the electrical length of the feeder, and β represents the number of radians of the traveling wave phase lag per unit length of the transmission line.

[0078] The total input impedance of the wide slot antenna element (Z SLSA ) can be obtained by the following formula

[0079] Z SLSA =Z l +Z stub #(4)

[0080] It can be seen from formula (4) that the equivalent capacitance and inductance of the loaded branches in the antenna wide slot and the input impedance of the antenna are closely related to the equivalent capacitance and inductance of the loaded branches. By changing the equivalent capacitance and inductance of the loaded branches in the antenna wide slot, that is, changing the length, width, shape and number of the loaded branches in the antenna wide slot, the harmonic impedance of the antenna input port can be modulated. When the antenna is connected to the transistor, the modulation of the second harmonic and higher harmonic impedance of the transistor can be achieved by adjusting these loaded branches, so that the harmonic energy of the RF power amplifier is superimposed on the fundamental wave, thereby improving the amplifier efficiency and power.

[0081] Embodiment 4

[0082] On the basis of the above embodiments, in order to more clearly demonstrate the structure and advantages of the RF power amplifier integrated antenna of the present invention, this embodiment is combined with the drawings in the specification and takes the integration of a GaN HEMT device of model CGH40010F and the wide slot antenna unit proposed in the present invention as an example for explanation.

[0083] The present invention can realize high-order harmonic modulation of multiple harmonic modulation PAs by adjusting the length, width and number of loading branches in the loading branch loading wide slot antenna, so that the harmonic power of the PA is superimposed on the fundamental wave and effectively converted into useful power, thereby realizing a high-efficiency PA integrated antenna module.

[0084] The radio frequency power amplifier integrated antenna of this embodiment includes an input matching network of a power amplifier, a transistor and a wide slot antenna unit, such as Figure 6 As shown. The integrated antenna of this embodiment is an inverse class F harmonic modulation PA integrated antenna, and the modulated PA harmonic order is 3. This embodiment also provides a design method for a radio frequency power amplifier integrated antenna, and the design method includes the following steps:

[0085] S1: Obtain the input impedance value of the transistor in the integrated antenna of the radio frequency power amplifier at a preset operating frequency and the impedance value corresponding to the current source end when the maximum efficiency is obtained.

[0086] Specifically, the input impedance value Z of the GaN HEMT device (CGH40010F) at 3.3 GHz, 3.6 GHz, and 3.8 GHz is obtained through the Load-pull program of the ADS software. S And the impedance value Zi when the current source end face obtains the maximum efficiency L-PAE , as shown in Table 1.

[0087] Table 1. Optimal output impedance and input impedance of PA transistors based on load-pull program simulation

[0088] frequency <![CDATA[Zi L-PAE (Oh)]]> <![CDATA[Z S (Oh)]]> 3.3GHz 42.4-j5.2 2.6-j12.4 3.6GHz 37.8+j3.4 3.3-j15.7 3.8GHz 32.5+j6.7 2.7-j20

[0089] Among them, Zi L-PAE It represents the output impedance of the transistor (GaN HEMT device) when the current source end face achieves maximum efficiency, Z S represents the input impedance of the transistor (GaN HEMT device), and j represents a complex unit.

[0090] S2: Designing an input matching network of the power amplifier according to the input impedance value.

[0091] According to the input impedance value Z S To design the input matching network for a power amplifier, see Figure 7 , Figure 71 is a structural diagram of an input matching network provided by an embodiment of the present invention. The input matching network of this embodiment includes a metal microstrip line TL1, a metal microstrip line TL2, a metal microstrip line TL3, a metal microstrip line TL4, a metal microstrip line TL5, a metal microstrip line TL6, a metal microstrip line TL7, a metal microstrip line TL8, a metal microstrip line TL9, a metal microstrip line TL10, a metal microstrip line TL11, a metal microstrip line TL12, a metal microstrip line TL13, a metal microstrip line TL14, a metal microstrip line TL15, a metal microstrip line TL16, a metal microstrip line TL17, a metal microstrip line TL18, a metal microstrip line TL19, a metal microstrip line TL20, a metal microstrip line TL31, a metal microstrip i1 , Metal microstrip line TL i2 , Metal microstrip line TL i3 , Metal microstrip line TL i4 , Metal microstrip line TL i5 , Metal microstrip line TL i6 , capacitor C1, capacitor C2, capacitor C3, capacitor C4, resistor R1 and resistor R2, wherein the metal microstrip line TL i1 , capacitor C4, metal microstrip line TL i4 , resistor R1 and metal microstrip line TL i6 - connected in series between the signal input and signal output of the input matching network, the signal output is connected to the gate of the transistor; the metal microstrip line TL i2 One end of the metal microstrip line TL i3 One end is connected to the capacitor C4 and the metal microstrip line TL i4 The capacitor C1 is connected in parallel to both ends of the resistor R1; the first end of the series structure formed by the metal microstrip line TL3, the metal microstrip line TL2, the metal microstrip line TL1 and the resistor R2 is connected to the power supply voltage input terminal, and the second end is connected to the metal microstrip line TL i4 and resistor R1; capacitor C2 is connected between the power supply voltage input terminal and the ground terminal, capacitor C3 is connected between the power supply voltage input terminal and the ground terminal, and the metal microstrip line TL i5 One end is connected to the metal microstrip line TL i4 and resistor R1.

[0092] Specifically, the length of the metal microstrip line TL1 is 5.2 mm, and the impedance is 56 Ω; the length of the metal microstrip line TL2 is 2.5 mm, and the impedance is 56 Ω; the length of the metal microstrip line TL3 is 2.8 mm, and the impedance is 56 Ω; i1 The length of the metal microstrip line TL is 10 mm, the impedance is 50 Ω i2 The length of the metal microstrip line TL is 9.2 mm, the impedance is 44 Ω i3 The length of the metal microstrip line TL is 17.2 mm, the impedance is 44 Ω i4 The length of the metal microstrip line TL is 5.8 mm, the impedance is 83 Ω i5 The length of the metal microstrip line TL is 4 mm, the impedance is 26 Ω i6 The length is 1mm and the impedance is 33Ω.

[0093] The capacitance value of capacitor C1 is 2.7 pF, the capacitance value of capacitor C2 is 5.6 pF, the capacitance value of capacitor C3 is 4.7 μF, and the capacitance value of capacitor C4 is 10 pF. The resistance value of resistor R1 is 50 Ω, and the resistance value of resistor R2 is 250 Ω.

[0094] S3: directly matching the input impedance of the wide slot antenna unit to the maximum efficiency impedance point or the maximum power impedance point or the intermediate impedance point between the maximum efficiency impedance point and the maximum power impedance point of the transistor by changing the size of the feed line and the wide slot in the wide slot antenna unit;

[0095] S4: Design a wide slot antenna unit according to the order of the harmonics of the power amplifier that needs to be modulated. By changing the number, shape and size of the loaded branches in the wide slot antenna unit, the harmonic impedance of the power amplifier is located at a preset open-circuit point or short-circuit point, so that the harmonic components of the power amplifier are superimposed on the fundamental wave, so as to improve the output power and efficiency of the power amplifier.

[0096] In this embodiment, an inverse F-class PA integrated antenna design is implemented. Therefore, in addition to realizing Zi on the current source end face of the transistor, L-PAE The fundamental impedance is matched. According to the design requirements of the inverse F-class PA, the second harmonic impedance of the transistor needs to be close to the open circuit point at the end of the current source, and the third harmonic impedance needs to be close to the short circuit point. The wide slot antenna unit is designed to achieve impedance modulation of the second and third harmonics. The wide slot antenna unit structure is as follows: Figure 8 shown.

[0097] Next, the designed RF power amplifier integrated antenna is jointly simulated and structurally optimized, and the current and voltage waveforms at the end of the transistor current source are obtained through simulation, such as Fig. 9 As shown, the current waveform is a square wave and the voltage waveform is a half-sine wave, indicating that the PA is operating in an inverse class F state. The loaded branch-loaded wide slot antenna of this embodiment realizes precise inverse class F harmonic modulation of the PA within the frequency band.

[0098] After processing and testing, the test results of the RF power amplifier integrated antenna designed in this embodiment are obtained, such as Fig.10 and Fig.11 As shown. Fig.10 It can be seen that within the frequency range of 3.3 to 3.8 GHz, the maximum PAE (power added efficiency) of the designed RF power amplifier integrated antenna is measured to be 70.1%, the maximum EIRP (equivalent isotropic radiated power) is measured to be 44.52 dBm, and the maximum output power (Pout) is measured to be 40.6 dBm. Fig.11It can be seen that the E-plane and H-plane radiation patterns of the RF power amplifier integrated antenna of this embodiment at the fundamental frequency, second harmonic frequency and third harmonic frequency are tested in the saturation state with the highest PAE. Compared with the fundamental frequency radiation power, the second and third harmonic radiation of the RF power amplifier integrated antenna of this embodiment in all directions are suppressed by more than 35dB. This ensures that the PA integrated antenna can obtain high PAE at the fundamental frequency.

[0099] It can be seen from the above embodiments that the integrated design method of the RF power amplifier and the antenna proposed in the present invention can realize a high-efficiency PA integrated antenna module, which fully meets the requirements of modern mobile communication systems for the integrated design of PA and antenna.

[0100] The present invention proposes a radio frequency power amplifier integrated antenna, including an input matching network of a power amplifier, a transistor and a wide slot antenna unit, wherein the input impedance of the antenna is used to match the output impedance of the PA, and multiple equivalent capacitor and inductor resonant networks are introduced through its multi-loaded branch structure, and the high-order harmonic impedance of the PA can be adjusted by adjusting the number, length, width and shape of these loaded branches (adjusting the number and size of equivalent capacitors and inductors), so that the harmonic impedance of the power amplifier is located at a preset open circuit point or short circuit point, so that the harmonic power of the PA is superimposed on the fundamental wave, and it is effectively converted into useful power instead of being wasted. This energy recovery and reuse can improve the overall efficiency of the PA integrated antenna.

[0101] In the several embodiments provided by the present invention, it should be understood that the apparatus and method disclosed by the present invention can be implemented in other ways. For example, the apparatus embodiments described above are only illustrative, for example, the division of the modules is only a logical function division, and there may be other division methods in actual implementation, for example, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed.

[0102] In addition, each functional module in each embodiment of the present invention may be integrated into one processing module, or each module may exist physically separately, or two or more modules may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of hardware plus software functional modules.

[0103] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A radio frequency power amplifier integrated antenna, characterized in that: The invention comprises an input matching network of a power amplifier, a power amplifier transistor connected to the input matching network, and a wide slot antenna unit directly connected to the output end of the power amplifier transistor, wherein: The wide slot antenna unit includes a feed line, a radiating body and at least one group of harmonic tuning components. A wide slot is opened inside the radiating body for achieving fundamental wave matching of the power amplifier; the harmonic tuning component includes a plurality of loading branches for tuning the harmonic impedance of the power amplifier; the plurality of loading branches extend from the edge of the wide slot to the inside of the wide slot and are symmetrically distributed on both sides of the feed line.

2. The radio frequency power amplifier integrated antenna according to claim 1, characterized in that: The radiation body is a metal square frame arranged on the front side of the substrate of the wide slot antenna unit, the wide slot is opened inside the metal square frame, the feed line is arranged on the back side of the substrate, and the feed line is perpendicular to the first outer edge of the metal square frame; The multiple loading branches in the harmonic tuning component are parallel to the feed line, and extend from a first edge of the wide slot and a second edge opposite to the first edge toward the inside of the wide slot respectively. The first edge and the second edge of the wide slot are perpendicular to the feed line.

3. The radio frequency power amplifier integrated antenna according to claim 2, characterized in that: Each group of harmonic tuning components includes four loading branches of the same size, namely the first branch, the second branch, the third branch and the fourth branch; The first branch node and the third branch node both extend from the first edge of the wide groove toward the inside of the wide groove and are perpendicular to the first edge of the wide groove; The second branch node and the fourth branch node both extend from the second edge of the wide groove toward the inside of the wide groove and are perpendicular to the second edge of the wide groove; The first branch and the second branch are arranged on the same straight line, located on the first side of the feeder and spaced apart from each other; the third branch and the fourth branch are arranged on the same straight line, located on the second side of the feeder and spaced apart from each other.

4. The radio frequency power amplifier integrated antenna according to claim 3, characterized in that: The wide slot further includes a third edge and a fourth edge perpendicular to the first edge and the second edge, the third edge is located on a first side of the feeder line, and the fourth edge is located on a second side of the feeder line; The distance between each of the loading branches and the third edge or the fourth edge is related to the operating frequency of the radio frequency power amplifier integrated antenna.

5. The radio frequency power amplifier integrated antenna according to claim 4, characterized in that: The interval W between the third edge and the fourth edge of the wide groove is f Determined by a quarter wavelength corresponding to the operating frequency of the radio frequency power amplifier integrated antenna; The distance between the lower edge of the first branch node and the lower edge of the second branch node and the third edge is W. f (n-1) / 2n; the distance between the upper edge of the third branch and the upper edge of the fourth branch and the fourth edge is W f (n-1) / 2n; Among them, n represents the harmonic tuning component used to tune the nth harmonic impedance of the power amplifier; the lower edge is the side of the first branch or the second branch away from the third edge; the upper edge is the side of the third branch or the fourth branch away from the fourth edge.

6. The radio frequency power amplifier integrated antenna according to any one of claims 1 to 5, characterized in that: The at least one group of harmonic tuning components includes a second harmonic tuning component and a third harmonic tuning component, wherein, The second harmonic tuning component is used to tune the impedance of the second harmonic of the power amplifier; the third harmonic tuning component is used to tune the impedance of the third harmonic of the power amplifier.

7. The radio frequency power amplifier integrated antenna according to any one of claims 1 to 5, characterized in that: The harmonic impedance is related to the size parameters of the loading branches; the size parameters include at least one of the shape, length, width of the loading branches and the distance between different loading branches.

8. The radio frequency power amplifier integrated antenna according to any one of claims 1 to 5, characterized in that: Tuning the harmonic impedance of the power amplifier includes tuning the harmonic impedance of the power amplifier to an open circuit state or a short circuit state; the impedance state of the harmonic impedance is related to the working type of the power amplifier.

9. The radio frequency power amplifier integrated antenna according to claim 8, characterized in that: When the power amplifier operates in a Class F operating state, the at least one set of harmonic tuning components is used to tune the second harmonic impedance of the power amplifier to a short-circuit state and to tune the third harmonic impedance of the power amplifier to an open-circuit state; When the power amplifier operates in an inverse class F operating state, the at least one set of harmonic tuning components is used to tune the second harmonic impedance of the power amplifier to an open circuit state and tune the third harmonic impedance of the power amplifier to a short circuit state.

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