1. Miniaturization, slicing and slicing: in order to meet the light, thin and short requirements of portable products represented by mobile phones, the packaging of quartz crystal oscillator has changed from traditional bare metal shell covered with plastic metal to ceramic packaging. For example, the volume of TCXO devices is reduced by 30-100 times. The thickness of TCXO with SMD package is less than 2mm, and the current 5 × 3mm devices are available. Crystal oscillator 2. High precision and high stability, the total precision of uncompensated crystal oscillator can also be achieved ± The frequency stability of VCXO can reach 25 ppm in the range of 10 ~ 7 ℃ ± The frequency stability of OCXO is 20-100ppm in the same temperature range ± 0001 ~ 5ppm, VCXO is controlled at 0 ± Below 25ppm. Crystal oscillator 3. Low noise, high frequency, frequency jitter is not allowed in GPS communication system. Phase noise is an important parameter to characterize the frequency jitter of oscillator. The phase noise performance of OCXO mainstream products has been greatly improved. Except VCXO, the highest output frequency of other types of crystal oscillator is not more than 200MHz. For example, ucv4 series VCO used in GSM and other mobile phones has a frequency of 650-1700mhz, a power supply voltage of 2.2-3.3v and a working current of 8-10ma. Crystal oscillator 4. Low power consumption, fast start, low voltage operation, low level drive and low current consumption have become a trend. The power supply voltage is generally 3.3V. For many TCXO and VCXO products, the current loss does not exceed 2mA. The rapid start-up technology of quartz crystal oscillator has also made a breakthrough. For example, vg-2320sc VCXO produced by Seiko of Japan is used in ± Under the condition of 0.1ppm, the frequency stabilization time is less than 4ms. The smdtcxo produced by Tokyo ceramic company of Japan can reach 90% of the rated value after 4 ms of oscillation start-up. The 10-25mhz OCXO products of oak company can reach the standard after preheating for 5 minutes ± 01 ppm. Crystal oscillator