An MCXO test system and its function in MCXO performances

Abstract

Describes an MCXO test system used mainly for MCXOs based on AT cut crystals. This system is composed of a temperature chamber, several switch groups, a PC, a high-resolution frequency meter, a frequency standard, a control system including a simulator and a controller. It can be used to produce the MCXOs with AT cut crystals and in the different temperature range /spl plusmn/1/spl sim/3/spl times/10/sup -7/ frequency-temperature stability can be obtained. In the test procedure for MCXOs, the system supplies MCXO standard temperature conditions, measures the frequency-temperature characteristics of the uncompensated MCXOs, obtains control signal (voltage, pulse width or digital code signal)-temperature sensed, signal data for the compensated MCXOs. According to the test data, the compensation table or equations for the completed MCXOs can be obtained. In the test system, high precision and fast speed frequency measurement combined with suitable computer control can be used instead of a complicated frequency synthesizer and is useful for MCXO production with different frequencies.