JPH0354904A - Uhf band oscillator - Google Patents

Abstract

PURPOSE:To obtain a compact, light and highly stable UHF band oscillator by constituting the UHF band oscillator of a Colpitts oscillator using a microstrip line and a transistor(TR) respectively as a resonance circuit element and a base resonance circuit. CONSTITUTION:The variable voltage VV of a 10-revolution herical potentiometer VR2 whose voltage can be adjusted is connected to a through capacitor C9 and supplied to a varrier cap diode VD1 through resistor R2 resistor R1 U-shaped resonance circuit 4 to vary the capacity of the diode VD1. The helical potentiometer VR1 applies a proper voltage to the base of a TR TR1 to adjust the current of the collector. When voltage is applied to the collector through a high frequency choke coil RFC, serial resonation occurs through capacitor C1 element 4 diode VD1, oscillation voltage appears on a resistor R3 to be the emitter and the voltage is fed back to the collector through the capacitor C2 to oscillate the oscillator.

Description

[Detailed description of the invention] {Industrial application field} The present invention relates to improvements in UHF band oscillators.

(Prior Art) Conventionally, modified Corbit oscillator circuits have often been used in converters and local oscillator circuits used in U-band radio equipment, such as television receivers, and the transmission elements of these oscillation circuits. Coils, thick conductors, microstrip lines, etc. are used as such.

In this case, L and C elements of a lumped constant circuit can be used in an oscillation circuit below the 4QQHHZ band, but
When the frequency becomes higher than this, it becomes an L, C circuit of a distributed constant circuit, and examples in this case include parallel line oscillators, butterfly oscillators, coaxial resonators, cavity resonators, and 1/2 wavelength of microstrip lines, 174 There are wavelength resonators, etc.

On the other hand, the oscillator that is the subject of the invention in this application is
This is a UHF band oscillator configured with a modified Kolbitz oscillation circuit in which a microstrip line is used as a resonant circuit element and a transistor is used as a common base circuit. First, we will explain the principle of the Kolbitz oscillation circuit, its embodiments, and the microstrip line. The explanation will be given with a 1/4 wavelength oscillator as the target.

Figure 1 shows a Corbits oscillation circuit with a common emitter circuit of transistor Tr1, in which the voltage appearing at the terminal of coil L1 is divided into appropriate proportions by capacitance dividing capacitors C2 and C3, and the voltage appearing at the terminal of C2 is fed back to the emitter circuit. A current flows through it, causing it to oscillate.

FIG. 2 shows the embodiment of FIG. 1, and the transistor Tr1
It is a Kolbitz oscillator with a common emitter circuit, and a double variable capacitor VC2 is used to divide the oscillator to change the frequency to the intended frequency. Since this circuit uses L and C elements of a lumped constant circuit, it cannot be used for a UHF91} oscillator.

Figure 3 shows an embodiment of a modified Kolbitz oscillator circuit in which the transistor Tr1 is used as a common base circuit. In this case, the oscillation frequency can be changed to any desired oscillation frequency by the single variable capacitor VC1, as shown in Fig. 2. The stator cannot be grounded.

In the case of Fig. 3, as can be understood from the figure, the circuit is simple and can be constructed with a single variable capacitor VC1, so even in UHF band oscillators, Kolbitz oscillation is often used as a modification of this base common circuit. The circuit is being applied.

Figure 4 shows a coaxial resonator of a modified Kolbitz oscillation circuit configured by fixing one end of the conductor L1 in a thick metal case and connecting a small single variable capacitor C1 to the other end, which is used in the UHF band. It is often used as a local oscillation circuit for television converters, and in this case, any oscillation frequency can be obtained by varying the variable capacitor MCI.

Figure 5 shows C1 on a substrate such as a baking plate or glass fiber.
, C2, VD1 and other capacitors and varicap diodes to fix the conductor L1 floating above the substrate, v■,
By varying the DC voltage of the varicap diode VD1, the capacitance of the varicap diode VD1 is changed to obtain an arbitrary oscillation frequency.

This is an example of a modified Kollbits oscillator circuit for the UHF band, and is often seen as a local oscillator in TVs and receivers for the LIHF band.

Figure 6 shows a resonant circuit element (18
) and a ground plane {3} as shown in the figure are provided around it, and the lower surface of the double-sided board (1) is provided with a through hole (6) and a through hole (11) for the d-through capacitor.
This shows a microstrip line 1/4 wavelength oscillator constructed with a continuous ground plane (2). As you can understand from the figure, this is a modified Lubitz oscillation circuit.

In this case, the upper and lower cut surfaces (9) of the board (1) are pasted with copper foil to prevent a potential difference from forming between the edged upper ground plane (3) and the lower continuous ground plane (2). The connection is made by electroless plating (8), and a large number of through balls (6) are provided on the ground plane (3) around the resonant circuit to connect the upper ground plane (3) and the lower continuous ground plane (2). are connected. The tip of the resonant circuit element (18) and the ground plane on the opposite side (
3), a single variable capacitor VC1 with a lumped constant is provided, and by varying this variable capacitor, an arbitrary oscillation frequency can be obtained.

(Problem to be Solved by the Invention) The above-mentioned is a UHF band oscillator, but as can be understood from each figure, the oscillation frequency is determined by the length of the resonant conductor and circuit element, so the fifth It is not possible to reduce the total area of the board (1) shown in FIG. Cavity resonators are difficult to manufacture, have a large volume, and have a large weight.
J} It has drawbacks such as being unsuitable as an oscillator to be incorporated into an IF band antenna system analyzer or the like because it cannot be made small and lightweight.

Therefore, the object of the present invention is to create a small, light carrier with high stability.
}-IF band oscillator.

(Means for Solving the Problems) This invention was made to solve the above-mentioned problems.This invention is a modified Kolbitz oscillator circuit in which a transistor is used as a common base circuit. The bottom surface of the double-sided board (1) is made into a continuous ground plane (2), and the ground plane (3) is provided around the top surface of the continuous ground plane (2).
3), a U-shaped resonant circuit element (4) of appropriate width and size, and a plurality of solder lands (
5) is an LJHF band oscillator characterized by being constructed using an etching method.

(Function) In the UHF band oscillator configured in this way,
Taking the microstrip line 1/4 wavelength oscillator (18) shown in FIG.
The principle operation of the E-band generator (50) will be explained.

Both sides of the dielectric I! In the double-sided substrate sandwiched between four dielectric materials, the molecules or atoms within the dielectric material have a positive or negative charge, and were initially in a completely neutralized state (the positive charge A state in which the average position and the average position of negative charges match and are balanced) When molecules or atoms are affected by an electric field, the average positions of positive and negative charges separate and become electric twins. .

Therefore, when an electric field is applied to the etched resonant circuit element, the charges inside the dielectric material move, the initial neutralized state is broken, and charges appear on the surface of the etched resonant circuit element.

That is, without the dielectric and the continuous ground plane, it is just a copper foil resonant circuit element and does not act as an inductance, but it is thought that it acts as an inductance due to the dielectric polarization effect of the dielectric.

In the case of Fig. 6, since it is a 1/4 wavelength oscillator, the resonant circuit element (18) is completely grounded at its base, and the closer it gets to the base, the weaker the supplied electric field becomes, and the electric dipole moment is small, so the inductance of the resonant circuit element (18) itself is small. On the other hand, the resonant circuit element (4) of the U-day F band oscillator (50) of the present invention has a U-shaped configuration as described above, and as shown in FIGS. The end of the capacitor is not directly grounded, and a high electric field exists in the part where power is supplied, but it is thought that an electric twin moment is acting on the average. In other words, since the inductance of the resonant circuit element (4) increases, when oscillating at the same frequency, the width of the resonant circuit element (18) of the 1/4 wavelength oscillator described above can be narrower, and the overall length can also be reduced. Since the inductance can be increased by making it shorter, the oscillation frequency band can also be widened.

(Embodiment) Next, the configuration of an embodiment of the present invention will be described with reference to FIGS. 7 to 10.

As shown in FIGS. 7 and 9, the F side of the glass fiber copper-clad double-sided board (1) is connected to a continuous ground ( 2), and the area around the top surface of the double-sided board (1) is grounded (3).
A U-shaped resonant circuit element (4) of appropriate width and size and a double-sided board (1) on which a plurality of solder lands (5) are etched are placed at an appropriate distance from the ground plane (3). A Kolbitz oscillator circuit is constructed as a modification of the base common circuit.

FIG. 8 shows its electrical circuit diagram. As shown in FIG. 9, chip capacitors 01 to C6 and chip resistor R
1 to R5, varicap diode MDI, transistor T"1, high frequency choke RFC, feedthrough capacitor 07
Solder ~C9 and coaxial cable 1.50 2 V, respectively.

In addition, on each of the four cut surfaces (9) of the double-sided board (1), connection surfaces (8) are made with copper-based conductive paint or electroless plating, etc., and a ground plane (3) on the top surface and a continuous connection on the bottom surface are formed. ground (2)
are connected respectively, and the upper and lower ground planes (3), (2) are also connected through the through hole (6), and R6,
R7, CIO, VRI, and VR2 indicate a resistor, a capacitor, a semi-fixed resistor, and a hemicarbotension meter for external control of this UHF band oscillator (50).

Next, the operation of the U-shaped band oscillator (50) of this embodiment constructed as described above will be explained with reference to FIG.

In this case, VR2 is a 10-turn helical potentiometer whose voltage can be finely adjusted; V
．． is connected to the Sadamichi capacitor C9, and is supplied to the varicap diode VD1 through R2→R1→U-shaped resonant circuit element (4), thereby varying the capacitance of the varicap diode VD1. Further, VR1 supplies an appropriate voltage to the base of transistor Tr1 to adjust the collector current. When a voltage is applied to the collector through the high frequency choke coil RFC, series resonance occurs from C1 → L1 → VD1, and an oscillation voltage appears at the emitter resistor R3, which is transmitted to C2.
is fed back to the collector and oscillates.

This oscillation output is derived by combining the oscillation voltage appearing at the emitter resistor 5R3 at 03 and passing through the attenuator of resistors R4 and R5 using a coaxial cable of 1.5D 2 V.

As mentioned above, this UHF band oscillator (50) has a narrow width of the resonant circuit element (4), and although the overall length is short, the inductance can be reduced to a large extent, so the size is reduced, and the UHF band oscillator (50) is made smaller.
A small F-band test oscillator, a band dip meter, a UHF?'6 high-frequency bridge with a built-in oscillator,
It can be easily incorporated into a UHF band antenna system analyzer, etc.

(Effect of the invention) As a result, tJ HF ? ! Oscillator (
50) can obtain the following effects.

《1) Any resonant frequency can be obtained by simply changing the width and length of the U-shaped resonant circuit element (4).
1. Each resistor R1 to R7 and each capacitor 01 to C10
As shown in Figures 7, 9, and 10, the mounting positions of the components can be fixed at fixed positions, which stabilizes the oscillation frequency and prevents parasitic oscillations and abnormal resonance of each element. Also, wiring work becomes easier.

(2) If the width of the U-shaped resonant circuit element (4) is widened, the characteristic impedance will be lowered, and if the width is narrowed, the characteristic impedance will be increased.

Furthermore, as shown in FIGS. 7, 9, and 10, any oscillation frequency bandwidth can be obtained by simply changing the size of the U-shaped resonant circuit element (4).

(3) Since the resonant circuit element (4) is shaped like a U, the 6th
Compared to the microstrip line 1/4 wavelength resonant circuit element (18) shown in the figure, the inductance increases, oscillation becomes easier, the area of the substrate (1) is reduced, and the U
The l-IF band oscillator (50) could be downsized.

That is, when comparing the oscillation data of both oscillators when manufactured with the same type of double-sided board (1), the following (A) and (B) are obtained.
become that way.

(A) Microstrip line 1/4 wavelength resonant circuit element oscillator data 1/4 wavelength resonant circuit element (18) 30IllIIl
Same element width 5mm (characteristic impedance approx. 40Ω) Capacitance change of air variable capacitor VC1 approx. 2.5~4PF5l
! Vibration frequency approximately 1300MHZ~1 200MHZ1/
4-wavelength resonant circuit element (18) and air variable condenser VC
The oscillation frequency is approximately 1300M due to the floating implantation of the first class.
HZ~1 200MHZL cannot be changed.

<8) Microstrip line U-shaped resonant circuit element Oscillator U-shaped resonant circuit element (4) External circumference dimensions: Right outer side 6 IIlm Top side 12.5 am Left outer side 6
1IIIl Center total length of the element 16.5 m Width of the element 2.8 mm (characteristic impedance approximately 50 Ω) Capacitance change of varicap diode MDI approximately 2 to 6 P
F Oscillation frequency approximately 1330MHz to 1050MHz (4)
As can be understood from the electrical circuit diagrams in Figures 7 and 8, none of the terminals of the U-shaped resonant circuit element (4) are directly grounded, so the 1/4 wavelength resonant circuit element in Figure 6 (18
), and R1 in Figure 8 is a resistor that supplies variable voltage in series to the varicap diode MDI, and is also a high frequency insulation resistor, so the resistance value is set high, and the varicap diode VD1 is also Since a capacitor with a high Q value is used, the stray capacitance at both ends of the U-shaped resonant circuit element (4) is small, and the coupling capacitor C1
Any oscillation frequency band can be obtained by simply selecting the capacity of the coupling capacitor C1 appropriately, and the oscillation frequency band can be lowered by increasing the capacity of the coupling capacitor C1.
If the capacitance of is made smaller, the oscillation frequency band becomes higher.

(5) Since the resonant circuit element (4) is made into a U-shape, the effective area of the dielectric part between the resonant circuit element (4) surface and the continuous ground plane (2) on the lower surface becomes large. The rate of reduction in the length of the resonant circuit element (4) has been improved, and the floating volume has therefore become smaller, making it easier to oscillate at high frequencies.

(6) As shown in Figure 10, by enlarging the U-shape of the resonant circuit element (4), the resonant circuit element (4)
The length is extended, the effective area of the electric conductor between it and the continuous ground plane (2) becomes larger, and the U-shaped recess formed by the U-shaped resonant circuit element (4) becomes larger. This increases inductance and has the effect of facilitating low frequency oscillation.

Next, in the UHF band oscillator (50) shown in FIG. 7, the connecting capacitors C7, C8, and C9 are shown to be directly soldered to the ground plane (3) on the top surface of the double-sided board (1). Depending on the form in which this U-shaped band oscillator (50) is used, it may be necessary to shield the oscillated radio waves, and the following problems may arise in this case.

(1> In order to stabilize the oscillation frequency, double-sided substrate (
1) The ground plane on the top surface (3) and the continuous ground plane on the bottom surface (3)
For 2), the wider the better.

(2) Shield the entire double-sided board (1) to suppress leakage radio waves.

(3) When housed in a metal case, the volume and weight of the UHF band oscillator (50) will increase.

(4) Easily connect to external control circuits.

(5) It is easy to construct a shield.

In order to satisfy the above (1) to (5), as shown in FIGS. 9 to 10 and 12 to 16,
The entire cut surface (9) of the double-sided board is used as the connection surface (8), and the side surfaces A. B. C.
Then, a frame body (14) is formed by surrounding the side surface D with a plurality of through holes (11) and soldering each corner from both sides. ) dotted line position 1 (
15) to form a shield case (16), and an upper lid (17) was provided.

In this case, the following actions and effects can be obtained.

(1) Connect the feedthrough capacitor C7 to the through hole (11) on side D.
, C8, and C9 were inserted and soldered, and the 1.50 2 V coaxial cable for deriving the high frequency output was passed through the through hole (11) and connected to the oscillation output circuit, so the coupling with the external circuit was stable and each We were able to suppress the anti-copper wave in the wiring circuit.

(2) Since the ground plane (3) on the top surface of the double-sided board (1) was extended to the inside of each side surface A, B, C, and D, the oscillation frequency was stabilized.

(3) Since the continuous ground plane (2) on the bottom surface of the double-sided board (1) is extended to the outside of each side surface A, B, C, and D, the shielding effect is improved.

(4) Since the entire shield case (16) including the frame (14) includes the double-sided board (1), the UH
``We were able to minimize the volume of the band oscillator and reduce its weight.

(5) We were able to make the work for the shield extremely easy.

(6) The entire cut surface (9) of the double-sided board is used as the connection surface (8), and the side surfaces A.
B, C. D. Since the frame body (14) surrounded by ) was able to minimize the potential difference between all the ground planes on the outside.

(Explanation of connection surface (8)) Bright [r cut surface (9) in l letter
was used as the connection surface (8) and connected to both the upper and lower surfaces of the double-sided board, respectively...'' means that the cut surface (9) was pasted with copper foil, electroless plated, and coated with copper-based conductive paint. Add processing such as coating, and cut in the same way as the top and bottom surfaces (9)
is considered a conductive surface, meaning that it is connected to both the upper and lower surfaces.

Next, in the UHF band, even if there are charts and complicated calculation formulas for determining the length, width, etc. of resonant circuit elements, it is extremely difficult to accurately clarify the stray capacitance of the circuit, and the resonant frequency is low. If so, shorten the length of the resonant circuit element, and conversely, if the resonant frequency is too high, narrow the width of the resonant circuit element a little.In the end, the only way is to cut and try. However, in UHF band oscillators, it is difficult to adjust the oscillation frequency by reducing the width and length of the resonant circuit element using the method described above.
It is not possible to obtain an I oscillator.

Therefore, as shown in FIG. 11, a solder land (5) is provided at the tip of the U-shaped resonant circuit element (4) with an appropriate gap (12). A varicap diode VD1 is connected between the solder land (5) and the ground plane (3), and a microcoil ( 13).

In this case, the following actions and effects can be obtained.

In other words, even if the microcoil (13) of the lumped constant circuit, which has an extremely small stray capacitance that is not affected by the dielectric, is connected to the U-shaped resonant circuit element (4) of the distributed constant circuit, there is no effect on the output of the oscillator. There is no change in the oscillation frequency.

For example, UHF band oscillation at 1250MHz! ! i (50)
When oscillating, 35Qm at point a shown in Figure 11
Although the high frequency voltage of V is measured, the microcoil (13)
At point b, where it passed through, only a value close to Qa+V could be measured.

In other words, since the oscillation frequency is high, the microcoil (13) has inductive reactance, whereas
In the case of the UHF band oscillator shown in FIG. 7, the terminal of the varicap diode vD1, that is, the U-shaped resonant circuit element
) can measure high-frequency voltage at the tip.
This can be thought of as a varicap diode VD1 having an inductance in series.

Also, as can be understood from Figure 11, the solder land (5)
The U-shaped resonant circuit element (4) becomes shorter by the gap (12) at an appropriate interval, and the oscillation frequency becomes higher. 7th
If a microcoil (13) having an inductance of an appropriate size, which is equivalent to the inductance of the U-shaped resonant circuit element (1) shown in the figure, is connected, the same oscillation frequency will be obtained. In reality, if you connect a microcoil (13) with a slightly larger inductance than this, the oscillation frequency will decrease, and if you widen the winding interval of this microcoil (13) to reduce the inductance, the oscillation frequency will increase. Become.

For example, in the case of a U-shaped F-band oscillator (50) composed of a U-shaped resonant circuit element (4) that oscillates at 1100 MHZ to 1350 MHZ, an enameled wire of φ0.23 ttm is used.
If a closely wound microcoil (13) with an inner diameter of 0.5a* and 3 turns is connected between points a and b in Fig. 11, the winding interval of this microcoil (13) can be By simply widening the range, it was possible to change the oscillation frequency in a range of about 0 to 40 MHz.

Therefore, since the oscillation frequency can be roughly adjusted by the winding interval of this minute coil (13), there is no need to cut the resonant circuit element and adjust its length and width as described above, and it is possible to use a UHFFtf oscillator with the same performance. has become easier to configure.

[Brief explanation of drawings]

Figure 1 is a basic wiring diagram of a Kolbitz oscillator circuit using transistors, Figure 2 is a wiring diagram of a Kolbitz oscillator in which transistors are configured with a common emitter circuit, and Figure 3 is a modified version in which transistors are configured with a common base circuit. A wiring diagram of a Kolbitz oscillator. Fig. 4 is a wiring diagram of a coaxial resonator of a modified Kolbitz oscillator circuit in which transistors are configured as a common base circuit. Fig. 5 shows a wiring diagram of a coaxial resonator of a modified Kolbitz oscillator circuit in which transistors are configured with a common base circuit. A wiring diagram of a modified Corbitz oscillator using a variable gap diode VD1, Fig. 6 is a wiring diagram of a modified Corbitz oscillator configured with a microstrip line 1/4 wavelength resonant circuit element (18), and Fig. FIG. 8 is a front view showing the upper surface of the double-sided substrate (1) of a UHF band oscillator (50) configured with a U-shaped resonant circuit element (4) according to an embodiment of the invention, and FIG. 9 is an electric circuit diagram thereof. 10 is a front view showing the etched surface of the double-sided substrate (1).
The figure is a front view showing the etching surface when the U-shaped resonant circuit element (4) is enlarged.
13), FIG. 12 is a front view of a double-sided board (1) with a shield case (16) attached, and FIG. Figure 14 shows the shield case (16).
FIG. 15 is a front view of the frame (14) of the shield case, and FIG. 16 is a D side view of the frame (14). The names of each part are not shown with numbers or alphabets. (1) is a double-sided board, (2) is a continuous ground plane (bottom surface), (
3) is the ground plane (top surface), (4) is the U-shaped resonant circuit element, (5) is the solder land, (6) is the through hole, (7
) is the 4 through holes for fixing the board, (8) is the connection surface, (9) is the cut surface, (10) is the through-hole capacitor, (11) is the through hole (
feedthrough capacitor, and coaxial cable), (1
2) is the gap, (13) is the microcoil, (14) is the frame 4, (15) is the dotted line position, (16) is the shield case,
(17) is the upper lid, (18) is the microstrip line 1/4 wavelength resonant circuit element, (A) is the right side of the shield case, (B) is the top side, (C) is the left side, (DJ is Lower side, (T'1) is a transistor, (C1) to (C6
〉 is a chip capacitor (C7) to (C9) is a feedthrough capacitor (CIO) is a ceramic capacitor
(R1) to (R5) are chip resistors, (R6) (R7)
is a carbon resistor, (VRI) is a semi-fixed resistor, (VR
2> is a 10-turn edge carbotension meter (RF
C) is a high frequency choke coil, (1.5D2V) is 5
00 coaxial cable, (al is U-shaped resonant circuit element (4
), (b) is the tip of the varicap diode (VD1
), (L1) is a resonant circuit element, (L2> is a microcoil, (MDI) is a variable capacity diode, (MCI) is a single air variable capacitor, (
VC2) is a double air variable capacitor, (+V) is a positive voltage power supply, (1) is a negative voltage power supply, (VV) is a variable voltage power supply of a variable cap diode (VD1), (50)
shows a U-shaped "band oscillator" of the present invention.

Claims (3)

[Claims] (1) In a modified Kolbitz oscillator circuit in which a transistor is used as a common base circuit, as shown in the figure, the bottom surface of a double-sided substrate (1) sandwiching a dielectric material is made into a continuous ground plane (2),
A ground plane (3) is provided around the top surface of the ground plane (3).
) and a U-shaped resonant circuit element (4) of appropriate width and size, and a plurality of solder lands (5).
) is formed by edging.
HF band oscillator. (2) As shown in the figure, the entire cut surface (9) of the double-sided board is used as the connection surface (8), and the side surfaces A, B, and C connected to the upper and lower surfaces of the double-sided board, respectively, and a plurality of through holes ( 11)
A frame body (14) is formed by surrounding the frame body (14) by soldering each corner from both sides, and soldering it to the dotted line position (15) on the ground plane (3) on the top surface of the double-sided board (1). The UHF band oscillator according to claim 1, comprising a shield case (16) and an upper lid (17). (3) As shown in the figure, a suitable gap (12) is made at the tip of the U-shaped resonant circuit element (4) and the solder land (
5). A varicap diode VD1 is connected between the solder land (5) and the ground plane (3), and a microcoil is connected between the tip of the U-shaped resonant circuit element (4) and the solder land (5). (13) The UHF band oscillator according to claim 1 or 2, wherein (13) is provided.