KR19990008581A - Voltage Controlled Oscillator Circuit for PCS Using Dielectric Resonator DR - Google Patents

Abstract

The present invention relates to a voltage controlled oscillation circuit for a PC (PCS) using a dielectric resonator (DR) capable of oscillating for 1.7 GHz voltage control when transmitting and receiving using a dielectric resonator.

The present invention is to use the dielectric resonator of 1.7GHz in the voltage controlled oscillator circuit for PCS, to reduce the phase noise by using a capacitor and a microstrip inductor, and also to eliminate the parasitic oscillation by using the capacitor and resistor In addition to excellent phase noise, a voltage controlled oscillation circuit capable of varying the range of use over 30 MHz is obtained.

[Representative diagram]

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Description

Voltage Controlled Oscillator Circuit for PCS Using Dielectric Resonator DR

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to personal portable communications (hereinafter referred to as PCS), and more particularly to a voltage controlled oscillation circuit for PCS (PCS) capable of oscillating for 1.7 GHz voltage control during transmission / reception using a dielectric resonator.

Recently, interest in PCS, the next-generation mobile communication, has been increasing, and the frequency of use has been confirmed, and the frequency of transmission is 1840 ~ 1870MHZ, and the reception frequency of 1752 ~ 1778MHZ.

In fact, the oscillator entering the terminal is 150MHZ lower frequency than the transmitter, and the transmission frequency is obtained by mixing and up-converting 150MHZ and 1.7GHZ, which has taken QPSK, so that the VOC of 1.7GHZ band is required. It is true.

VCOs produced in the past are composed of LC oscillation circuits, and these LC oscillation circuits provide a wide frequency variable range, but the phase noise characteristic, which is one of the important parameters of the VCO, is inferior. have.

In order to improve such a problem, a mobile phone is using a dielectric resonator (Dielectric Resonator) that has excellent characteristics such as high frequency variation and phase noise in the VCO.

However, such a dielectric resonator has a problem in that it is difficult to obtain a wide variable range.

The present invention has been made to solve such a conventional problem, PC (V) using a dielectric resonator (DR) using DR as a PCS VCO, but excellent in phase noise and can vary the range of use over 30MHZ (PCS) The purpose is to provide a voltage controlled oscillation circuit.

The present invention for achieving the above object is characterized by the configuration to perform voltage controlled oscillation using a dielectric resonator of 1.7GHz.

1 is a voltage controlled oscillation circuit diagram for PCS of the present invention.

Explanation of symbols for the main parts of the drawings

TR: Transistor C1-C8: Capacitor

D1: Variable capacitance diode DR: Dielectric resonator

R1-R7: Resistor XL1-XL4: Microstrip Inductor

Hereinafter, an embodiment of a voltage controlled oscillation circuit for a PC (PCS) using the dielectric resonator DR of the present invention will be described in detail with reference to the accompanying drawings.

1 is a circuit diagram of the present invention, which comprises a capacitor C8 and a microstrip inductor XL4, and a phase noise reduction circuit 10 for reducing phase noise and a base connected to an output side of the phase noise reduction circuit 10. FIG. And a parasitic oscillation blocking circuit 20 which is connected to a collector of the transistor TR and a collector of the transistor TR, and which is connected to a collector of the transistor TR to block parasitic oscillation. A capacitor C7 connected to the collector of TR to determine the center frequency of the use band, a dielectric resonator DR connected in series with the capacitor C7 and oscillating lower than a self resonance frequency according to a peripheral circuit, A capacitor C6 connected to the contact point of the capacitor C7 and the dielectric resonator DR to widen the frequency variable range and an emitter of the transistor TR to widen the frequency variable range. A capacitor C2 to be carried out, a microstrip inductor XL1 connected in parallel to the capacitor C2 to control the flatness and the electric field strength of the output signal in the use band range, and an emitter of the transistor TR. And a? Type attenuator 30 composed of resistors R5-R7 that lower the output level.

In the drawings, reference numerals C1, C3 and C9 are capacitors, R1, R2 and R4 are resistors, D1 is a variable capacitance diode, and XL3 is a micro strip inductor.

However, since the dielectric resonator DR oscillates lower than the self resonant frequency according to the peripheral circuit, a dielectric resonator higher than the actual oscillation frequency should be used.

According to the present invention configured as described above, when the power is supplied, a forward bias is applied to the transistor TR so that a current flows through the transistor TR.

Therefore, when current flows in the transistor TR, the oscillation is caused by a negative resistance circuit composed of the capacitors C1 and C7 and the dielectric resonator DR having a resonant frequency of 2530 MHZ. A signal is transmitted to the emitter of the transistor TR and output through the capacitor C3.

In addition, the capacitor C6 and the diode D1 are connected in series and connected in series with the dielectric resonator DR. When a voltage from OV to + 3V is applied from the power supply terminal VT, the variable capacitance diode D1 is applied. ), The reverse bias is increased, and if the reverse bias is increased in this way, the capacitance of the variable capacitance diode D1 decreases, thereby increasing the frequency.

On the contrary, when the reverse bias of the variable capacitor diode D1 decreases, the capacitance value of the variable capacitor diode D1 increases and the frequency decreases.

In addition, the present invention can reduce the pulling even if the output level is slightly reduced by connecting the π-type attenuator 30 composed of resistors R5-R6 on the output end side.

In general, the radio wave transmitted and received by the antenna of the PCS terminal is processed based on the signal generated by the voltage controlled oscillation circuit. According to the voltage controlled oscillation circuit of the present invention as described above, the conventional LC oscillation circuit is used. Phase noise, harmonics, etc. are very excellent, and the quality of the terminal can be improved.

As described above, the present invention can use a dielectric resonator of 1.7 GHz band to drive the oscillator for transmission and reception mounted inside the PCS terminal, repeater, and base station at low voltage, and obtain low phase noise as well as a flat output signal. There is an effect that can be obtained.

Claims (1)

A phase noise reduction circuit 10 including a condenser C8 and a microstrip inductor XL4 to reduce phase noise, and a base connected to an output side of the phase noise reduction circuit 10, and having a transistor conducting when power is applied. ), A parasitic oscillation blocking retrospective 20 which is connected to the collector of the transistor TR and is composed of a capacitor C5 and a resistor R3 to block parasitic oscillation, and a collector of the transistor TR. A capacitor C7 which determines the center frequency of the band used, a dielectric resonator DR which is connected in series with the capacitor C7 and oscillates below the self resonance frequency according to a peripheral circuit, and the capacitor C7 and the dielectric resonator ( A condenser C6 connected to the contact point of DR to perform a wide range of frequency variable range, a condenser C2 connected to an emitter of the transistor TR to widen the frequency variable range, and A microstrip inductor XL1 connected in parallel to the condenser C2 to control the flatness and electric field strength of the output signal in the use band range, and a resistor connected to the emitter of the transistor TR to reduce the output level. A voltage controlled oscillation circuit for a PC (PCS) using a dielectric resonator (DR), comprising a? Type attenuator (30) composed of (R5-R7). [drawing] 1