TW391090B - Control structure of oscillator for preventing frequency offset - Google Patents

Abstract

The present invention provides a control structure of oscillator for preventing frequency offset comprising a separated circuit, a first conductor layer and a second conductor layer. The separated circuit has a plurality of grounding elements connected to the first conductor layer and connected as a common ground on the first conductor layer, then connected to the second conductor layer so as to control the oscillator operation to prevent the frequency offset. Furthermore, the invention can be applied to control the structure of oscillator IC with an external oscillator and connect the ground of IC with the ground of oscillator in parallel as a common ground on the first conductor layer; then, connecting to the second conductor layer that providing the same effect for preventing frequency offset.

Description

This case is a structure for preventing frequency offset in a controlled oscillator, especially a structure for preventing shift in a voltage controlled oscillator (vc0). + «See more Most commercial wireless communication products, such as DECT and GSM ’are used in their RF systems. TJ) D (Time Divi si〇n

Dup 1 ex) method. However, they are prone to encounter the problem of sisters, that is frequency drift. This is because the power amplifier (turn-on) is turned on after the frequency-locking (synthesized) is completed. Most products use a narrow-bandwidth voltage-controlled oscillator 101 or a well-shielded (shieiding) case to solve this problem, so that the cost is greatly increased. See Figure 2. In fact, the general voltage controlled oscillator uses a microstrip line ii (tank circuit) on a tank circuit. This is where the frequency drift comes from the power amplifier. Because the ground current 12 of the microstrip line 11 runs on the ground plane below the microstrip line 11, its magnitude is less than or equal to 1011 ^. During the period when the voltage-controlled oscillator pin is fixed, there is no interference from the power amplifier, so the ground current 12 can return to ground smoothly. See Figure 3. However, when the power amplifier is turned on, the ground current 21 of a high-power power amplifier is a large current, generally 200 mA. 'It will force the ground current 12 of the microstrip line 11 to change direction (fi〇w | direct ion). In this way, the impedance on the microstrip line will be changed | and the frequency of the voltage controlled oscillator will be changed.

D: \ champion \ CASE \ po_new \ pdl277. Ptd Page 4 r Outside °, Figure ㈤. It is customary to make RF circuits on printed circuit boards. Therefore, / t directly grounds the voltage path of the oscillator via a short path. It is also not an example of 41 t; ^; ^ There will be many ground points 42 on the circuit board, and each ground element will be on a serious ground plane. This is the cause of the difference as shown in Figure 2. This is more specific in high-power transmission power systems, which is to address the lack of the above-mentioned conventional knowledge. This can prevent a mining-route structure, which makes time sharing. Under the duplex (TDD) system, you can: 疋, receive frequency, and then improve the accuracy of data reception. Secondly, the implementation of this case can even achieve the purpose of reducing costs. News broadcast ^ The above purpose 'The control of this case to prevent frequency drift when vibrating: a two-cavity separation circuit, a first conductor layer and a second conductor layer group. The circuit has a plurality of grounding elements on the first conductor layer. After being connected in parallel, a common ground point is obtained, and then it is connected to the second conductor layer. [: The ground point of the grounding element is connected to the common ground point and connected to the other conductor on the -conductor layer, so the large current of the power amplifier will not interfere with the ground current of the control vibrator, so it can reach iL frequency protection The purpose of drifting can also save costs. The control oscillator is a voltage-controlled oscillator (vc0) with a frequency exceeding 100 MHz, and the separate circuit is fabricated on a printed circuit board (PCB). The first conductor layer and the second conductor layer are located on the printed circuit board. A discrete circuit contains one of the active circuits of the controlled oscillator, or an active circuit plus an active circuit

D: \ champion \ CASE \ po_new \ pdl277. Ptd page

Or even a resonator (buffer), a variety of combinations. A conductor layer of the ground elements of the conductive layer is connected. Second conductor. In other words, a common ground point of the ground plate is used to gather the first plurality of ground points at one place, and then the ground layer is connected to the common ground point with a ground plane point. A method for connecting the second conductive layer to one of the common ground points is a conductive means, which connects (parallel) the plurality of ground points of the grounding elements to adjacent ground points, and then connects the points. Of course, the common ground point is a welding kick point. The control oscillator is further electrically connected to a power amplifier. The power amplifier generates a large current on the second conductor layer during operation. As described above, the second conductor layer is a ground plate. Of course, the discrete circuit is a discrete RF circuit (discrete rf Ί circuit) ° j. The structure to prevent frequency drift in the control oscillator can be composed of an integrated circuit and a resonant circuit. The body circuit has a first ground terminal 'and a second ground terminal of the resonance circuit connected in parallel to the first conductor layer, and then connected to the second conductor layer' also has the effect of preventing frequency drift. I got a deeper understanding: Figure 1 · Control of the connection between the oscillator and the power amplifier using conventional electricity; Figure 2: Current and ground current of the conventional microstrip line; Figure 3: Interference from the ground current of the conventional power amplifier; Four: Circuit structure of the conventional voltage controlled oscillator

D: \ champion \ CASE \ po_new \ pdl277. Ptd Page 6 V. Description of the invention (4) Figure 5: Connection between the voltage-controlled oscillator and its buffer in this case; Figure 6: Circuit structure 1 of the voltage-controlled oscillator in this case; Figure 7: The circuit structure of the voltage-controlled oscillator in the case 2; Figure 8: The circuit structure of the voltage-controlled oscillator in the case is applied to the integrated circuit. The main figure numbers in the figure are as follows: 3 2: Buffer 41: Ground element 61: Common ground point 63: Resonator 71: Integrated circuit 31: Voltage controlled oscillator 3 3: Ground current 51: Common ground point 6 2 Active circuit 64: Buffer 72: Resonator Please refer to Figure 5. The phenomenon that the frequency of the output of the voltage-controlled oscillator 31 changes with the load is called the pulling effect. When the frequency locker locks the frequency, the ground current of the voltage controlled oscillator flows through the ground plate to form a closed loop. However, this ground current 33 will be changed by the area of the ground plate of the oscillator controlled by the voltage through which the ground current of the power amplifier flows. Therefore, the best way to improve the interference of the power amplifier is to connect all the ground points 311 and 321 of the voltage controlled oscillator 31 and its buffer 32 to the first conductor layer of the printed circuit board (PCB) to form a common ground point. Connect to a ground plane on another level. In this way, the large current flowing through the power amplifier cannot interfere with the ground current of the voltage controlled oscillator 3 3 ^ In other words, when the voltage controlled oscillator 31 locks the frequency, the power is turned on again.

V. Description of the invention (5) In the case of the device, the output impedance of the voltage-controlled oscillator 31 and the output terminal 322 of the buffer 32 will not change accordingly, and the frequency will not drift. See Figure 6. In the actual voltage-controlled oscillator, we can find many grounding elements 41 (usually resistors or capacitors). These grounding elements 41 are conventionally connected to the grounding board of the printed circuit board. However, in this case, they are Connect in parallel 'to form a common ground point 51 on the upper conductor layer of the printed circuit board (pCB), and then connect it to the lower ground plate. That is, only one point on the ground is the ground point of the voltage controlled oscillator. See Figure 7. Another structure can distinguish the voltage-controlled oscillator: it is divided into two parts, each of which is mixed or combined to form a common ground point, and then connected to the ground plate of the printed circuit board. These three parts are the active circuit, the resonator, and the buffer. In FIG. 6 series, the grounding elements 41 of the active circuit 62 and the resonance circuit 63 are connected in parallel to form a common grounding point 61; and the grounding elements 41 of the buffer 64 form a common grounding point, and then they can be connected to the ground plate. The main reason for doing this is that the most disturbed part of the voltage controlled oscillator is the active circuit. See 囷 八. In addition, this case can be further applied to the integrated circuit 71 (IC) of the voltage controlled oscillator j. The voltage controlled oscillator is generally equipped with an external resonator 72. The ground point (pin) 722 of the integrated circuit 71 (IC) of the voltage controlled oscillator and the ground point 721 of the resonator 72 are connected in parallel to form a common ground point 73. By using this common ground point 73 and then connecting it to the ground plate of the printed circuit board, the purpose of preventing frequency drift can also be achieved. Of course, the application of this case is not limited to a voltage controlled oscillator. While in

D: \ charapion \ CASE \ po_new \ pdl277. Ptd Page 8 V. Description of the invention (6) In application, in addition to discrete circuits, the application of integrated circuits can also include the connection of external resonators . In summary, the 'ground case of the ground element controlling the oscillator' is formed in parallel on the first conductor layer of the printed circuit board to form a common ground point, and then connected to the ground plate of the printed circuit board to prevent The purpose of frequency drift. Anyone familiar with the art can use this case to make a case, but none of them can be as good as those attached to the scope of patent application. >

Claims (1)

Sixth, please patent the scope of L. Kinds of structures to prevent frequency drift in the oscillator, including: —Separate military circuit with a plurality of grounding elements; The second layer of the “Zhao Zhao layer” is used to electrically connect these grounding elements, and The connection-elements can be connected together to obtain a common ground point; and the first conductor layer is electrically connected to the common ground point to prevent a frequency drift when the control oscillator 2 operates. k The structure for preventing frequency drift in the controlled oscillator according to item 1 of the scope of patent application, wherein the control oscillator is a voltage controlled oscillator 3 The frequency is prevented in the controlled oscillator described in item 1 of the scope of patent application A floating structure in which the frequency is a frequency exceeding 00 MHz. In order to prevent frequency drift in the control oscillator described in item 1 of the scope of the patent application, the discrete circuit is constructed on a printed circuit board 5 as described in item 4 of the scope of patent application. The structure for controlling frequency shift in the oscillator, wherein the first guiding layer-$ is brushed on the circuit board. ΗGuang and the first -conductor layer are located in the control field described in the section of the scope of the patent = application patent: 2% of which the separated circuit is the Λ initial circuit (ac 11 ve c 1 rcu 11) including the control vibration exhauster. Work 7. Control vibration exhaustion as described in item 6 of the scope of patent application: ==) the separation The type circuit further includes the control 8. Prevent the frequency rent D: \ chajnpion \ CASE \ po_new \ pdl277. Ptd in the control vibrator described in item 7 of the patent application fan garden. : Structure, wherein the separate circuit further comprises a buffer (Ibuffer) of the control vibrator. The structure for preventing frequency drift in the controlled oscillator described in item 6 of the scope of patent application, wherein the discrete circuit further includes the control oscillator—the punch (U) uf fer). 10. The structure for preventing frequency drift in the controlled oscillator as described in item i of the scope of patent application, wherein the common ground point is used to gather the multiple ground points of the ground elements of the first conductor layer in one. And then connected to the second conductor layer. 11. The structure for controlling frequency drift in the controlled oscillator according to item 10 of the scope of patent application, wherein the second conductor layer is a ground plane. 12. The structure for controlling frequency drift in the controlled oscillator described in item i of the patent application scope, wherein the second conductor layer is a ground plane. 13. The structure for preventing frequency drift in the control oscillator as described in item 12 of the scope of patent application, wherein one point of the ground plate is connected to the common ground point. 14. The structure for controlling frequency drift in the controlled oscillator according to item 1 of the scope of the patent application, wherein the connection method between the second conductor layer and the common ground point is a conductive method. 15. The structure for preventing frequency drift in the controlled oscillator according to item 14 of the scope of the patent application, wherein the conductive means is to connect each of the plurality of ground points of the grounded components to an adjacent ground point, and then Connect to this common ground point. D: \ champion \ CASE \ po_new \ pdl277. Ptd Page 11 VI. Application Outline II 16. The structure for controlling frequency drift in the controlled oscillator as described in item 15 of the scope of patent application, where the common ground point is A solder spot. 17. The structure for controlling frequency drift in the controlled oscillator described in item 1 of the scope of patent application, wherein the common ground point is a solder point. 18. The structure for preventing frequency drift in the controlled oscillator according to item 1 of the scope of the patent application, wherein the controlled oscillator is further electrically connected to a power amplifier (p0Wer ampl i f i er). 1 9. The structure for controlling frequency drift in the controlled oscillator according to item 8 of the patent application scope, wherein the power amplifier generates a large amount of electricity when the power amplifier is in operation on the second conductor layer. 20. The structure for controlling frequency drift in the controlled oscillator according to item 19 of the scope of patent application, wherein the second conductor layer is a ground plate. 21. The structure for controlling frequency drift in the controlled oscillator according to item 1 of the scope of the patent application, wherein the separated circuit is a separated radio frequency circuit (d i s c r e t e R F c i r c u i t). 2 2. A structure for controlling frequency drift in an oscillator, including: an integrated circuit having a first ground terminal; a resonant circuit having a second ground terminal for connecting the first ground terminal to A common ground point; and a first conductor layer 'for electrically connecting the integrated circuit and the resonance circuit' and electrically connecting the common ground point; and a second conductor layer for electrically connecting to the common ground point In order to prevent a frequency drift when the controlled oscillator is operating. 23. Prevent the frequency in the controlled oscillator as described in the patent application No. 22 D: \ champion \ CASE \ po_new \ pdl277. Ptd Page 12 6. The structure of the scope of patent application, wherein the control oscillator is a voltage controlled oscillator 24. The control oscillator described in item 22 of the scope of patent application A structure for preventing frequency shift, wherein the frequency is a frequency exceeding 100 MHz. The structure for controlling frequency shift in the controlled oscillator according to item 22 of the scope of patent application, wherein the discrete circuit is fabricated on a printed circuit board (CB), and the first conductor layer and the second conductor layer The system is located on the printed board. 26. The structure for preventing frequency shift in the controlled oscillator as described in item 22 of the scope of the patent application, wherein the second conductor layer is a ground plane. 27. The point of the ground plate in the structure for preventing frequency = shift in the controlled oscillator described in item 26 of the scope of patent application is connected to the common ground point. 28. The structure for controlling drift prevention in the oscillator according to item 22 of the patent application scope, wherein the common ground point is a solder point. 29_ The structure for preventing drift in the control oscillator according to item 22 of the scope of patent application, wherein the control oscillator is further electrically connected to a power amplifier with amp 1 i f i er). 30. The structure for controlling frequency drift in the controlled oscillator as described in item 29 of the scope of the patent application, wherein the power amplifier flows on the second conduction layer during operation. Wang Badian