Ultra-wideband passive structure for generating orthogonal signals
By adding the inductive coupling structure of the adjustment coil in the inner and outer rings of the main coupling coil in RF communication, the problem of difficult control of the phase and amplitude error of the quadrature signal in the wide band is solved, and a single-stage ultra-wideband orthogonal signal generation is realized, which improves the system performance and the practicality of integrated circuits.
Patent Information
- Application Number
- CN202420856923.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-23
- Publication Date
- 2024-12-06
- Estimated Expiration
- 2034-04-23
AI Technical Summary
In the field of radio frequency communication, it is difficult for the prior art to maintain the 90-degree phase error and amplitude error of the orthogonal signal in a wide frequency band at the same time, resulting in the impact of system performance, especially in integrated circuits with large space occupation and limited practicality.
The method of adding adjustment coils to the inner or outer ring of the main coupling coil is adopted to control the phase and amplitude error of the quadrature signal by adjusting the inductive coupling to realize single-stage ultra-wideband quadrature signal generation.
The generation of orthogonal signals with small phase errors and amplitude errors in broadband is realized, which avoids the need for multi-stage network cascade and improves the practicality and performance of integrated circuits.
Smart Images
Figure CN222128047U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of phase shifting, in particular to an ultra-wideband passive structure for generating orthogonal signals. Background Art
[0002] In the field of radio frequency communication, orthogonal signals are often used to modulate signals to achieve high-capacity signal transmission. Orthogonal signals can also isolate different signals. Therefore, the generation of orthogonal signals is very common in the radio frequency field, especially in radio frequency integrated circuits and millimeter wave integrated circuits. In some ultra-wideband systems, the generation of orthogonal signals needs to maintain a constant 90-degree phase error and a very small mismatch in amplitude error to ensure that the system can maintain relatively good performance in a wideband frequency range, such as an important indicator in wireless systems: image rejection ratio.
[0003] The wireless communication system architecture and the system architecture diagram of orthogonal signal generation are shown in the figure Figure 1 As shown, Figure 1 The IQ signal generator IQG decomposes the local oscillator signal LO into orthogonal signals with a phase difference of 90 degrees, and mixes the I signal and Q signal up to the radio frequency RF through I-Mix and Q-Mix respectively. Finally, the up-mixed signal is amplified by the output end of the power amplifier PA to complete the signal transmission. The performance of IQG determines the sideband suppression of the transmission, that is, the image signal. If the phase error and amplitude error of IQG are too large, it will greatly affect the output performance of the transmitter.
[0004] like Figure 2 As shown, the more classic method of generating orthogonal signals is to use a polyphase structure, that is, to use RC for phase shifting. The classic polyphase network structure is divided into two structures, type-I and type-II. The phase shift of type-I can always be maintained at 90 degrees, but the amplitude error between its orthogonal signals is only consistent at the poles formed by RC, that is, the 90-degree phase shift is a broadband range, but the frequency range of the amplitude mismatch is relatively narrow; type-II is just the opposite, the amplitude mismatch of the output signal can always be kept consistent, but the 90-degree of the orthogonal signal is only consistent at the poles formed by RC. For this reason, in order to simultaneously keep the 90-degree phase error of the orthogonal signal small and the amplitude error of the orthogonal signal small within a wide frequency band, it is generally necessary to cascade multiple stages of polyphase networks, such as Figure 2 The figure shows a three-stage polyphase filter network structure. Vin+ and Vin- are input differential signals with a phase error of 180 degrees. After passing through the polyphase network, the phases of the output differential Vout-i and Vout-q signals are 0 degrees, 180 degrees, 90 degrees, and 270 degrees, respectively.
[0005] In the microwave and millimeter wave frequency bands, the more common structure for achieving a 90-degree phase shift is the 3dB orthogonal coupler structure. This phase shifter structure is generally called a hybrid structure, which can achieve a phase difference of 90 degrees between a pair of signals. Its structure is as follows Figure 3 As shown, the phase between the coupling port CPL and the THR port is 90 degrees, and the amplitude is -3dB. This structure has a very wide bandwidth and is therefore widely used. In the field of integrated circuits, coupling lines generally require the design of transmission lines, which occupy a considerable area of the chip. Therefore, their practicality in terms of integration is often limited. Generally, the benefits of using them can only be realized in extremely high frequency bands, or they are often used when there is ample space on the PCB board.
[0006] In the field of integrated circuits, coil coupling is a common method. Its basic idea is based on the lumped model, using the coupling between inductors to form a similar Figure 4 This lumped-type model is similar to a polyphase filter, where either the phase is constant over a wide band, but the amplitude error is very narrow over the entire frequency band; or the amplitude is constant over a wide band, but the phase error is very large (see Figure 5 ), so generally multiple couplers are needed to be cascaded to achieve a very good 90-degree phase shift in a wide bandwidth while keeping the amplitude error very small, such as Figure 6 shown.
[0007] Therefore, it is necessary to provide a new structure for generating orthogonal signals to solve the above problems. Utility Model Content
[0008] The utility model aims at an ultra-wideband passive structure for generating orthogonal signals. On the basis of the structure of generating orthogonal signals based on lumped model inductive coupling, an adjustment coil close to the inner and / or outer ring of the main coupling coil is used to control the phase and amplitude of the orthogonal signal. In the structure, ultra-wideband orthogonal signal generation can be realized in a single stage, and at the same time, the phase error and amplitude error of the output signal are kept very small within the broadband.
[0009] The technical solution to achieve the purpose of this utility model is:
[0010] An ultra-wideband passive structure for generating orthogonal signals, the ultra-wideband passive structure comprising an inductively coupled orthogonal generation circuit and an adjustment coil, wherein:
[0011] The regulating coil is composed of two regulating inductors connected end to end, and the regulating coil is arranged in the inner circle or the outer circle of the main coupling coil of the inductive coupling type orthogonal generating circuit.
[0012] Further: the inductively coupled orthogonal generation circuit includes first and second coupled inductors, first to sixth capacitors and an adjustment coil, wherein:
[0013] Two ends of the first capacitor are respectively connected to one end of the second capacitor and one end of the third capacitor, and the other end of the second capacitor and the other end of the third capacitor are respectively grounded;
[0014] A common end of the first capacitor and the second capacitor is connected to one end of the first coupling inductor, and the other end of the first coupling inductor is connected to one end of the fourth capacitor and one end of the sixth capacitor respectively;
[0015] A common end of the first capacitor and the third capacitor is connected to one end of the second coupling inductor, and the other end of the second coupling inductor is connected to one end of the fifth capacitor and the other end of the sixth capacitor respectively;
[0016] The other end of the fourth capacitor and the other end of the fifth capacitor are grounded respectively;
[0017] There is coupling between the first coupled inductor and the second coupled inductor to form a main coupled coil.
[0018] Furthermore: the regulating coil also includes a switch, two ends of the switch are respectively connected to one end of the two regulating inductors, and the other ends of the two regulating inductors are connected.
[0019] Furthermore: the ultra-wideband passive structure includes at least two adjustment coils, at least one adjustment coil is arranged in the inner circle of the main coupling coil, and at least one adjustment coil is arranged in the outer circle of the main coupling coil.
[0020] Further: the common end of the first capacitor and the second capacitor serves as the input end IN, the common end of the first capacitor and the third capacitor serves as the coupling end CPL, the common end of the fourth capacitor and the sixth capacitor serves as the through end THRU, and the common end of the fifth capacitor and the sixth capacitor serves as the isolation end ISO.
[0021] Furthermore: the ultra-wideband passive structure is also provided with a ground shielding structure.
[0022] Compared with the prior art, the utility model has the following significant advantages: the ultra-wideband passive structure for generating orthogonal signals of the utility model, based on the structure of generating orthogonal signals by inductive coupling based on a lumped model, adds an adjustment coil to the inner and / or outer circles of the main coupling coil to control the phase and amplitude errors of the orthogonal signals. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 It is an existing transmitter architecture of a wireless communication system based on orthogonal signals.
[0024] Figure 2 It is a classic Type-II three-level polyphase network structure.
[0025] Figure 3 It is an existing orthogonal signal generating structure based on a coupler structure.
[0026] Figure 4 It is an existing inductively coupled orthogonal signal generation structure based on a lumped model.
[0027] Figure 5 It is a schematic diagram of the amplitude error of the coupler structure generated by the existing lumped model.
[0028] Figure 6 It is a broadband orthogonal signal generation structure formed by multiple lumped couplers.
[0029] Figure 7 It is a schematic diagram of the traditional lumped model coupler orthogonal generation circuit.
[0030] Figure 8 It is the actual layout of the orthogonal generation circuit based on the lumped model coupler.
[0031] Figure 9a It is the frequency response characteristic of the orthogonality amplitude error of the traditional lumped model coupler.
[0032] Figure 9b It is the frequency response characteristic of the orthogonal phase error of the traditional lumped model coupler.
[0033] Fig.10 It is a schematic diagram of the orthogonal signal generation circuit of the improved lumped model coupler.
[0034] Fig.11a It is the change in amplitude error after adding the inner and outer closed loops.
[0035] Fig.11b It is the change in phase error after adding the inner and outer closed loops.
[0036] Fig.12 An embodiment of the utility model provides an ultra-wideband passive structure for generating orthogonal signals, in which both the inner and outer rings of the mutual inductance coil are added with adjustment coils.
[0037] Fig.13 An ultra-wideband passive structure for generating orthogonal signals based on a ground shielding layer is provided in one embodiment of the utility model.
[0038] Fig.14 An embodiment of the utility model provides an ultra-wideband passive structure for generating orthogonal signals by adding a configurable adjustment coil. DETAILED DESCRIPTION
[0039] The following is a detailed description of the implementation of the utility model in conjunction with the accompanying drawings. Although certain embodiments of the utility model are shown in the accompanying drawings, it should be understood that the utility model can be implemented in various forms and should not be interpreted as being limited to the embodiments described here. On the contrary, these embodiments are provided to provide a more thorough and complete understanding of the utility model. It should be understood that the drawings and embodiments of the utility model are only for exemplary purposes and are not intended to limit the scope of protection of the utility model.
[0040] The term "including" and its variations used in the present invention are open inclusions, i.e., "including but not limited to". The term "connected" may be directly connected or indirectly connected through an intermediate component. The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments". The relevant definitions of other terms will be given in the following description.
[0041] It should be noted that the concepts such as "first" and "second" mentioned in the present invention are only used to distinguish between devices, modules or units, and are not used to limit these devices, modules or units to be different devices, modules or units, nor are they used to limit the order or interdependence of the functions performed by these devices, modules or units.
[0042] The traditional inductive coupling type is designed based on a lumped model, and its circuit diagram is as follows Figure 7 As shown (two inductors L0 are coupled to form the main coupling coil), the physical implementation layout is as follows Figure 8 As shown in Figure 2, due to its unclear distributed effect, its phase and amplitude mismatch cannot meet the requirements at the same time, such as Figure 9a and 9b shown.
[0043] The utility model proposes a novel ultra-wideband passive structure for generating orthogonal signals, and adopts a method of adding a closed regulating coil to the inner circle and / or outer circle of a main coupling coil to control the phase and amplitude errors of the orthogonal signals.
[0044] like Fig.10 As shown, the ultra-wideband passive structure includes first and second coupled inductors, first to sixth capacitors and an adjustment coil, wherein:
[0045] Two ends of the first capacitor are respectively connected to one end of the second capacitor and one end of the third capacitor, and the other end of the second capacitor and the other end of the third capacitor are respectively grounded;
[0046] A common end of the first capacitor and the second capacitor is connected to one end of the first coupling inductor, and the other end of the first coupling inductor is connected to one end of the fourth capacitor and one end of the sixth capacitor respectively;
[0047] A common end of the first capacitor and the third capacitor is connected to one end of the second coupling inductor, and the other end of the second coupling inductor is connected to one end of the fifth capacitor and the other end of the sixth capacitor respectively;
[0048] The other end of the fourth capacitor and the other end of the fifth capacitor are grounded respectively;
[0049] There is coupling between the first coupled inductor and the second coupled inductor to form a main coupled coil;
[0050] The regulating coil is composed of two regulating inductors connected end to end, and the regulating coil is arranged on the inner circle or the outer circle of the main coupling coil.
[0051] In one embodiment of the present invention, two inductors L1 and L2 are added between the main coupled inductor L0, and L1 and L2 each form a closed loop (ie, the above-mentioned regulating coil), such as Fig.10 and Fig.12 As shown in the figure, L1 forms the inner ring and L2 forms the outer ring. Since the inner ring is small, its effect on the phase is to increase or decrease the overall phase error; the outer ring will greatly improve the relative error between low frequency and high frequency, that is, make the phase error become relatively flat, as shown in the figure below. Fig.11a and 11b As shown in the figure, by adding these two loops, the 90-degree phase shift error of the coupler in the full frequency band (between f1 and f2) can be greatly improved. At the same time, while the orthogonal phase is improved (based on + / -1deg), the amplitude error is also relatively improved (based on + / -1dB error).
[0052] It should be noted that, taking into account the different design processes actually used, the actual winding width and spacing are different, and a method of making a closed coil only on the outside of the coil or only inside the coil to improve the orthogonal characteristics, at the same time, a method of combining multiple closed coils in the inner ring or outer ring, and a method of placing the closed coil in a non-geometrically symmetrical position around the main coupling coil can also be used.
[0053] In one embodiment of the present invention, considering that a ground plane shielding structure can also improve the phase to a certain extent, a ground shielding structure can be added to the structure of the present invention, such as Fig.12 As shown, the error of the orthogonal phase is further controlled.
[0054] In one embodiment of the utility model, not only can a closed coil be added to the inner and / or outer coils of the main coupling coil, but a non-closed coil can also be added with a switch to perform configurable closure, so that the characteristics of the orthogonal signal generator in different frequency bands can be changed by configuring different states, such as Fig.14 As shown. Fig.14 In the figure, two switches S1 and S2 are added as a schematic diagram, indicating that the conduction of the switches can be changed by software configuration to realize the on and off of the coil, so as to achieve the adjustment of the orthogonal phase and amplitude error of the orthogonal signal.
[0055] It should be noted that the metal level of the closed coil can be high-level metal or low-level metal of the process used, and is not affected by the distance between the closed coil and the main coupling mutual inductance coil, nor is it limited by the width of the metal closed coil.
[0056] It should be noted that the present invention is not limited to the field of integrated circuits. Any structure of multi-layer coil winding, generating orthogonal signals, and measures for improving broadband orthogonal signal errors using closed coils should be considered within the scope of the present invention.
[0057] It should be noted that in the structure for generating orthogonal signals, the main coupling coil also has certain winding changes to improve the relative positions of the CPL and THRU signals. However, if a closed coil method is also used, it should also be regarded as within the technical scope of the present utility model.
[0058] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the utility model patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.
Claims
1. An ultra-wideband passive structure for generating orthogonal signals, characterized in that: The ultra-wideband passive structure includes an inductively coupled orthogonal generation circuit and an adjustment coil, wherein: The regulating coil is composed of two regulating inductors connected end to end, and the regulating coil is arranged in the inner circle or the outer circle of the main coupling coil of the inductive coupling type orthogonal generating circuit.
2. The ultra-wideband passive structure for generating orthogonal signals according to claim 1, characterized in that: The inductively coupled orthogonal generation circuit comprises first and second coupled inductors and first to sixth capacitors, wherein: Two ends of the first capacitor are respectively connected to one end of the second capacitor and one end of the third capacitor, and the other end of the second capacitor and the other end of the third capacitor are respectively grounded; A common end of the first capacitor and the second capacitor is connected to one end of the first coupling inductor, and the other end of the first coupling inductor is connected to one end of the fourth capacitor and one end of the sixth capacitor respectively; A common end of the first capacitor and the third capacitor is connected to one end of the second coupling inductor, and the other end of the second coupling inductor is connected to one end of the fifth capacitor and the other end of the sixth capacitor respectively; The other end of the fourth capacitor and the other end of the fifth capacitor are grounded respectively; There is coupling between the first coupled inductor and the second coupled inductor to form a main coupled coil.
3. The ultra-wideband passive structure for generating orthogonal signals according to claim 1 or 2, characterized in that: The regulating coil further comprises a switch, two ends of the switch are respectively connected to one end of the two regulating inductors, and the other ends of the two regulating inductors are connected.
4. The ultra-wideband passive structure for generating orthogonal signals according to claim 1 or 2, characterized in that: The ultra-wideband passive structure includes at least two adjustment coils, at least one adjustment coil is arranged in the inner circle of the main coupling coil, and at least one adjustment coil is arranged in the outer circle of the main coupling coil.
5. The ultra-wideband passive structure for generating orthogonal signals according to claim 2, characterized in that: The common end of the first capacitor and the second capacitor serves as the input end IN, the common end of the first capacitor and the third capacitor serves as the coupling end CPL, the common end of the fourth capacitor and the sixth capacitor serves as the through end THRU, and the common end of the fifth capacitor and the sixth capacitor serves as the isolation end ISO.
6. The ultra-wideband passive structure for generating orthogonal signals according to claim 1 or 2, characterized in that: The ultra-wideband passive structure is also provided with a ground shielding structure.