JPS61172421A - Tuner - Google Patents

Abstract

PURPOSE:To attain high shield performance without generating the reduction in Q by giving a parasitic distributed constant capacitor to a lumped constant inductor so as to generate a resonance tuning circuit, surrounding earth conductors having a gap to the peripheral and surrounding a conductor material having a low absorption loss performance around the resonance tuning circuit nearly. CONSTITUTION:Inductor electrodes 11, 12 are installed oppositely so that the earth terminals are placed oppositely at the front and rear sides of a dielectric circuit board 10 and the earth conductor having gaps 17, 18 at the outside of the inductor electrodes is surrounded. Further, a shield device 13 made of a conductor material having a low absorption loss performance is surrounded and a coupling secondary coil 19 with other circuit network is installed. Thus, the inductors and capacitors are formed incorporatedly to make the shield performance highly stable, the tuning frequency and the tuning Q are made highly accurate and stable to realize the thin profile shield form.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a tuning device that can be used in radio, television transmitters or receivers, and other communication equipment in general.

Background of the Invention In recent years, the number of radio and television broadcast waves and communication waves from communication devices has increased, and the performance of tuning devices that select the frequency of the radio waves desired to receive requires high stability and reliability. . On the other hand, reducing manufacturing costs and saving space for receivers, transmitters, and communication devices in which tuning devices are installed is also a major issue, and drastic changes are needed to improve tuning circuit components and shielding methods for high-frequency parts, which are particularly difficult to rationalize. There is a particular need for technology development.

The conventional tuning device mentioned above will be explained below with reference to the drawings.

FIG. 6 shows a perspective view of a conventional tuning device. In FIG. 6, 1 is an inductor component, and 2 is a capacitor component, which are connected by circuit conductors 4 and 6 provided on a substrate 3 to form a tuned circuit. Further, electrical connections with other circuit networks (not shown) are performed by sending and receiving signals via circuit conductors 7, which are obtained by a secondary coil 6 or the like. Reference numeral 8 denotes a shield case, which is provided with a coupling window 9 to generate mutual coupling with other adjacent tuning circuits (not shown).

(For example, "Solid State FM Receiver" Fukui.

Suzuki, Denki Shoin, pages 224-230).

Problems to be Solved by the Invention However, with the above configuration, it is difficult to install each component at a predetermined setting position with high precision, and as a result, the tuning frequency as a high frequency tuning device cannot be set at the set target. It deviated greatly from the value and it was impossible to converge to a constant value. Furthermore, it is difficult to determine the positional relationship between the shield case and each tuning component with high precision, resulting in unstable shielding performance and a large deviation in the tuning frequency and Q value from the set target values. Furthermore, it is difficult to improve the positional relationship between the secondary coil and the inductor components with high precision, and as a result, the amount of signals sent and received deviates significantly from the set target value. It is difficult to arbitrarily and easily adjust the degree of coupling with other adjacent tuning devices, and the frequency characteristics deviate greatly from the set target value. As described above, the above configuration has a problem in that there is a limit to realizing a high performance tuning device.

In view of the above problems, the present invention integrally forms an inductor and a capacitor, highly stabilizes the shielding performance, and improves the precision and stability of the tuning frequency and y4Q.
In addition, the present invention provides a tuning device that realizes an ultra-thin shield configuration, allows easy control of the degree of coupling with adjacent tuning circuits, and highly stabilizes secondary coil coupling with other circuit networks. It is.

Means for Solving the Problems In order to solve the above problems, the tuning device of the present invention includes inductor electrodes that are arranged facing each other on the front and back sides of a dielectric circuit board, the ground terminals of which are set in different opposing positions. Then, a ground conductor with a gap is installed surrounding the outside of the inductor electrode, so that the setting can be controlled arbitrarily, and a shield made of a conductive material with low absorption loss performance is installed surrounding it, and other circuit networks are installed. It is equipped with a configuration in which a secondary coil for coupling is installed.

According to the above-described configuration, the present invention forms a resonant tuned circuit by making a distributed constant capacitor parasitic on a lumped constant inductor, and surrounds and installs a ground conductor having a gap around the outer periphery of the resonant tuned circuit. It is possible to ensure high shielding performance without reducing the Q value, and by arbitrarily controlling the settings in the middle, the degree of coupling with the adjacent resonant tuned circuit can be arbitrarily controlled, resulting in low absorption loss. By enclosing a conductive material with high performance in close proximity to the resonant tuned circuit, high shielding performance can be ensured without causing a drop in the Q value, and it can be used as a secondary coil for connection with other circuit networks of the same type as the resonant tuned circuit. By using the forming means, the degree of bonding can be ensured in a highly stable manner.

Embodiments Below, a tuning device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a configuration diagram of a tuning device in an embodiment of the present invention.

In Figure 1, (a) is a surface view, (0)) is a side view, and (0)) is a side view.
c) shows the back view.

In FIG. 1, 1o is a dielectric substrate, 11 and 12 are inductor electrodes, and the ground terminals of the inductor electrodes 11 and 12 are set so as to be in different opposing positions. 13 and 14 are shielding devices, which are made of conductive material with low absorption loss performance. 16 and 16 are ground conductors, and the ground conductors 15 and 16 are connected to the gap 1.
7 and 18. A secondary coil 19 is connected to the circuit network 20.

The operation of the tuning device configured as described above will be explained.

(Hereinafter, in explaining the operation of the resonant circuit section, the inductor electrode will be explained as a transmission line electrode, and the resonant circuit section constituted by each of the inductor electrodes will be explained as a tuner.) Figures 2 (a) to (e) show the present invention. This is an equivalent circuit for explaining the operation of the tuner. In FIG. 2(a), a signal source that generates a voltage e for a transmission path formed by transmission path electrodes 70 and 71 having an electrical length l and having their ground terminals set in opposite directions. 72 is connected to the transmission line electrode 7o to supply a signal. As a result, a traveling wave voltage "A" is excited at the open terminal at the tip of the transmission line electrode 7o.

On the other hand, since the transmission line electrode 71 is disposed close to and facing the transmission line electrode To or is arranged in parallel with the above-mentioned transmission line electrode To, a voltage is induced by mutual induction. The traveling wave voltage induced in the open terminal at the tip of the transmission line electrode 71 is assumed to be eB.

Since the respective ground terminals of the transmission line electrodes 70 and 71 are set in opposite directions, the induced traveling wave voltage eB has an opposite phase to the excited traveling wave voltage A. Since the forward end of the transmission line is open, each of the traveling wave voltages eA and eB forms a voltage standing wave in the transmission line formed by the transmission line electrodes To and 71. Here, if the voltage distribution coefficient indicating the distribution mode number of the voltage standing wave in the transmission line electrode 70 is expressed as K, then the voltage distribution coefficient in the transmission line electrode 71 can be expressed as (1-K).

Therefore, the potential difference V generated at any opposing portion of the transmission line electrodes 70 and 71 is calculated as follows: V = K@A - (1-K) eB
・−・・−(1) Here, if the respective transmission line electrodes 70 and 71 have the same electrical length l, then 11B = eA-°°-(2), so the potential difference V in the first equation is V = K
eA ten (I K) eA = “A ゛... me)
becomes. That is, a potential difference V can be generated in all parts where the transmission line electrodes To and 71 face each other.

Here, it is assumed that the transmission line electrodes 0 and 71 have the electrode width W and the electrode thickness is thin. Furthermore, it is assumed that they are opposed to each other at a distance d via a dielectric material having a dielectric constant ε. In this case, the capacitance C0 formed per unit length of the transmission line is co=6°C8- (e).

Therefore, the transmission path shown in FIG. 2(a) is a transmission path including a distributed capacitor 73 of C0 determined by the formula 6 in the unit length shown in FIG. As shown in FIG. 2 (0), the path is a distributed inductor component consisting of integrated distributed inductors 77 and 78 and a distributed capacitor 73 due to the distributed inductor component of the transmission path and the lumped inductor component generated due to the bent shape of the transmission path. It can be expressed equivalently as a constant circuit.

Next, the relationship between the formation of the distributed capacitor 73 and the electrical length l of the transmission path will be explained. The characteristic impedance z0 per unit length in the transmission path as shown in FIG. 3(a) can be expressed by the equivalent circuit shown in FIG. 3(b). Its characteristic impedance z0 is generally as follows. Here, if the transmission path is lossless, then In most of the embodiments of the tuner of the present invention, this assumption can be ignored, and to simplify the explanation, the characteristic impedance 0 shown in the following equation 8 is used. The capacitance C0 in the eighth equation is the same as the unit capacitance C0 in the transmission path determined in the sixth equation. In other words, the characteristic impedance per unit length in the transmission line z0
is a function of the capacitance C0, which is also a function of the dielectric constant ε8° of the dielectric material involved in the capacitor C0, the width W of the transmission line electrodes, and the spacing d between the respective transmission line electrodes.

As described above, the equivalent reactance X generated at the terminal of a transmission line whose characteristic impedance per unit length in the transmission line is 20, whose electrical length is l, and whose tip is open is x = -2OCotθ・...It can be expressed as (9). here! ,=21−・・・・・・(10
) λ, especially in the case where the equivalent reactance x is X≦0 Old... (12). That is, the equivalent reactance at the terminal of the transmission line can be the capacitive reactance. Therefore, when θ corresponds to Equation 11 depending on the electrical length l of the transmission path, a capacitor can be formed by setting the electrical length j to λ/4 or less, for example. The capacitance C of the capacitor that can be formed can be realized by changing θ, that is, by setting the electrical length l of the transmission path, as shown by the following.

FIG. 4 is a diagram illustrating the operation mode of the transmission line explained in Equations 9 to 13 above. FIG. 4 shows how the equivalent reactance X generated at the terminal changes in accordance with the change in the electrical length l of the transmission line with its tip in an open state. As is clear from Fig. 4, the electrical length j of the transmission line is less than λ/4 or between λ/2 and 4.
In cases such as at λ/3, it is possible to form a negative terminal reactance, ie equivalently to form a capacitor. Furthermore, under conditions that generate negative terminal reactance, the electrical length of the transmission line l
By arbitrarily setting the capacitance C, it is possible to realize the capacitance C to an arbitrary value.

The capacitor C formed in this way is shown in FIG.
) can be equivalently replaced as a lumped constant capacitor 79 shown in FIG. The inductor formed by combining the distributed inductor component existing in the transmission path and the lumped inductor component generated by bending the transmission path can be equivalently replaced as the lumped constant inductor 8o. If the ground terminal is expressed as a common ground terminal in FIG. 2(d), it is clear that the final lumped constant capacitor 7 is shown in FIG. 2(e).
9 and a lumped constant inductor 80, and can realize a tuner.

Next, by surrounding the outer periphery of the tuner with ground conductors 16 and 16, it functions to prevent electrostatic coupling with other circuit networks (not shown). Further, by providing gaps 17 and 18 in the shape of the ground conductors 16 and 16, a short-circuited secondary coil is not formed, thereby preventing a decrease in the Q value in the tuner.

Next, by arbitrarily setting and controlling the widths of the gaps 17 and 18 between the ground conductors, the degree of coupling between adjacent tuners can be arbitrarily changed, and the band and Q value of the frequency characteristics of the tuners can be arbitrarily changed.

Next, by surrounding the tuner with a shield made of a conductive material having low absorption loss performance, a high shielding performance can be obtained while preventing a decrease in the Q value in the tuner.

The secondary coil for coupling with other circuit networks and the tuner are coupled by inductive coupling and distributed capacitive coupling.

Note that the inductor electrode in the above embodiment.

Metal conductors as earth conductors and secondary coils.

Printed metal foil conductors, thick film conductors, thin film conductors, etc. can be used. Also, if you form an inductor electrode by combining different types of the above conductors, mica! A resin-based printed circuit board, a glass-based printed circuit board, etc. can be used.

In addition, as the shield device in the above embodiment, copper,
Silver, gold, aluminum, brass, bronze, etc. can be used.

The two circuit networks include an amplifier, two oscillators, and a mixer.

A modulator, demodulator, etc. will be installed.

Effects of the Invention As described above, the present invention provides an inductor electrode having respective ground terminals or a common terminal located in different opposing positions, a dielectric substrate, a ground conductor having a gap, and a ground conductor having a gap. Moreover, by providing a ground conductor that can be arbitrarily set and controlled in the gap, a shield made of a conductive material with low absorption loss performance, and a secondary coil for coupling using the same type of forming means as the inductor electrode, it is possible to The inductor and capacitor can be integrated into one by using a suitable construction and manufacturing method. Further, the form of the tuning device can be made ultra-thin, and at the same time it can be made smaller and lighter.

Furthermore, a modularized tuning device having no mechanically movable parts can be realized, and the tuning frequency and tuning Q can be made extremely stable. Furthermore, since there is no connection lead interposed between the inductor and the capacitor, there are no unstable elements such as unnecessary lead inductance and stray capacitors, and a highly stable tuning device can be realized. In addition, it is possible to rationalize manufacturing and save resources, and the manufacturing cost of the tuning device can be significantly reduced. Furthermore, the number of parts in the tuning device can be reduced, and parts inventory and manufacturing management can be rationalized, resulting in a significant reduction in total cost.

By providing a gap in the ground conductor that surrounds the tuner, it is possible to prevent the short circuit effect of the tuner, and to greatly enhance the shielding effect from other circuit networks while preventing the Q value of the tuner from decreasing. , a highly stable tuning device can be realized.

Further, it is possible to extremely easily set and control the frequency characteristic band and Q value in double tuning, and to maintain highly stable double tuning performance.

Furthermore, even if the shield device is installed very close to the tuner, the tuning Q will not be lowered. Therefore, an ultra-thin and ultra-compact shielding form can be realized, and it is highly stable and has a high tuning Q. A highly tuned device can be realized.

Since the degree of coupling between the tuner and the secondary coil can be maintained extremely stably, the stability of the tuning device system including other coupled circuit networks can be increased. In particular, it is possible to realize a tuning device with extremely good skirt attenuation characteristics in a band above the tuning frequency. In other words, in the conventional tap coupling method using capacitors, the bypass filter effect works,
Compared to the point that the skirt attenuation characteristic in the band above the tuning frequency is not practical, this can be sufficiently improved.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a tuning device in an embodiment of the present invention;
2 to 4 are diagrams illustrating the operating principle of the tuning device in the same embodiment, and FIG. 5 is a perspective view of the conventional tuning device. 1o...Dielectric substrate, 11, 12...
Inductor electrode, 13, 14...shield device,
15.16... Earth conductor, 17.151...
...Gap, 19...Secondary coil, 2o.
...Circuit network. Name of agent: Patent attorney Toshio Nakao and one other name
1 Figure 2 Figure 2 Figure 3 (α) (b) Figure 4 □I? [1044 Town Books (Ai, e Figure 5 ρ

Claims (6)

[Claims] (1) First and second electrodes, each having an arbitrary electrical equivalent length, are installed facing each other with a dielectric interposed therebetween, and the ground terminal or common terminal of each of the first and second electrodes is connected to a portion facing each other. A first terminal is provided at any position of the first or second electrode, and this first terminal and the ground terminal or a common For a two-terminal tuning circuit network having a terminal as a second terminal, transmitting and receiving electrical signals with another circuit network is performed using a terminal that is electrically connected to the other circuit network and of the first or second electrode. A closed-loop secondary electrode surrounding a part or all of the electrode is used, and a shielding device is installed on one or both sides facing the first and second electrodes, the part or all of which is made of a metal material with relatively small absorption loss. Tuning device. (2) The tuning device according to claim 1, wherein a part or all of the shielding device is made of steel. (3) The tuning device according to claim 1, wherein a part or all of the shielding device is made of an alloy containing a copper material. (4) The tuning device according to claim 1, wherein the closed loop secondary electrode is made of the same material and construction method as the first or second electrode. (5) The tuning device according to claim 1, wherein the first and second electrodes have at least one bent portion. (6) The tuning device according to claim 1, wherein the first and second electrodes have a spiral shape.