• 대한전기학회논문지:시스템및제어부문D
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• 제53권10호
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• pp.727-732
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• 2004

TCXO is one of the most important component in communication systems. We present a analytic method approach to design the Temperature Compensated Circuit. The conventional method for extracting the circuit parameters, which are for thermistor, Colpitts and frequency control circuit is the trial and error correction. In this paper, we analyse the temperature compensating circuit to extract TCXO circuit parameter. In order to show the validity of this paper, we have designed and implemented the 10MHz TCXO. The fabricated TCXO shows 1ppm frequency drift characteristic over the temperature range of -40℃∼85℃.

• 대한전자공학회논문지SD
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• 제43권8호
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• pp.6-12
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• 2006

최근 이동통신 시스템의 급속한 발전에 따라, 관련된 이동통신 부품의 개발이 요구되고 있으며, 특히 기존의 이동통신 부품 소형화와 병행하여, 주변회로 및 소자와의 복합화가 진행되고 있다. 본 논문에서는 WCDMA(UMTS)용 다중출력 VC-TCXO (Voltage Controlled-Temperature Compensated Crystal Oscillator)는 내부에 CMOS 인버터를 추가로 내장하여 기본적인 정현파(Clipped sinewave) 출력에 추가로 CMOS 출력을 가능하게 하였고, 또한 WCDMA 시스템에서 요구하는 VC-TCXO 특성을 만족하였다. 또한 기준 발진기의 중요한 특성인 위상잡음(Phase noise) 특성 및 주파수 단기 안정도 특성(Frequency short term stability)도 WCDMA(UMTS)의 기준을 만족하였다. 본 논문에서는 기준 주파수로 26MHz를 사용하고 있지만, 10MHz에서 40MHz까지 다양하게 응용될 수 있다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2005년도 추계종합학술대회
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• pp.841-844
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• 2005

Multi-output VC-TCXO (Voltage Controlled-Temperature Compensated Crystal Oscillator) for WCDMA has integrated the additional CMOS inverter, so it can be normal clipped sinewave output and additional CMOS output and it can be satisfied the VC-TCXO Characteristics that WCDMA system required. In this paper, however 26MHz is used for reference frequency, similarly and practically, it is usable from 10MHz to 40MHz, Most important factor to integrate CMOS inverter internally is the isolation between normal output and additional output. For this, it is separated in package design, due to this, when it isn't used additional output, it shows the same electrical performance, when it is used additional output, it has minimum-rized the interference. and then the important characteristics in reference oscillator are met to WCDMA system's requirements, like phase noise and frequency short term stability.

• 한국통신학회논문지
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• 제18권5호
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• pp.739-745
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• 1993

이동통신 기기에서 온도에 대해서 고안정의 주파수 합성기를 구현함은 중요하다. 그런데, 고안정의 주파수 합성기를 구현하기 위해서는 기준 주파수를 제공하는 발진기가 온도에 대해서 안정해야만 한다. 본 논문에서는 이러한 필요성에 따라서 디지털 방식을 이용한 TCXO가 구현된다. DTCXO는 온도 감지부, 제어부, VCXO로 나뉜다. 구현된 DTCXO의 주파수 안정도는 평균 0.94ppm이다. 이는 아나로그 방식을 이용한 TCXO의 안정도인 2.5ppm과 비교해볼 때, 향상된 결과이다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(5)
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• pp.33-36
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• 2001

An automatic TCXO frequency-temperature test apparatus was firstly developed by using thermoelectric device may. The developed system swing stably the test temperature range from -40$^{\circ}C$ to +80$^{\circ}C$ for about 1 hour The rising temperature ratio was fairly linear with time in this test temperature range. The temperature could be controlled error in error range of ${\pm}$0.05$^{\circ}C$ in this system. The frequency-Temperature properties of TCXO or the thermoelectric properties of other electric device.

• 전자진흥
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• 제24권7호
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• pp.56-57
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• 2004

• 한국재료학회:학술대회논문집
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• 한국재료학회 1998년도 한국재료학회 춘계학술발표강연 및 논문개요집
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• pp.94-94
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• 1998

• 한국재료학회:학술대회논문집
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• 한국재료학회 1998년도 IUMRS-ICEM ABSTRACT BOOK
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• pp.109.3-109
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• 1998

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.33.3-33
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• 2002

Pseudolite (PL) is a kind of signal generator, which transmits GPS-like signal at the ground. However our own made PL is different from a GPS satellite in clock accuracy. GPS satellites are synchronized by use of high precision atomic clocks. But because our PLs use low cost temperature controlled oscillators (TCXO), so it is very difficult to synchronize them. Hence, we should install reference station and use Differential GPS (DGPS) algorithm to calculate user position. By use of this method, we already developed indoor navigation system a few years ago. We named it as 'Asynchronous Pseudolite Indoor Navigation System'. However, this system requires that sampling times of all the receivers...

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -2
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• pp.1200-1203
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• 2002

A temperature compensated Crystal Oscillator is widely used for the stable frequency source of mobile communication equipments. Recently, it has become necessary to reduce power consumption of TCXOs. In this paper, we have proposed a TCXO using weak inversion MOS transistors and have evaluated its fundamental characteristics.