| Benefitting from the low loss and intrinsic noise characteristics of the optical fiber links, transferring high stable frequency signals through them has many advantages, and has been an active field of research over the past few decades. Driven by the requirements of the applications and costs, delivering radio frequency (RF) signals has become a trend. However, optical fiber suffers from environment perturbations, which will lead to variations of the delay and phase of the transferred RF signal. The research works in this dissertation are aiming to provide solutions to improve the stabilizing speed while correcting the RF phase or to enlarge the tuning range when compensating the optical delay. Based on these solutions, a downlink transmission system for wideband RF signal is also designed, which is suitable for antenna array applications.To improve the stabilizing speed while correcting the RF phase, a stable delivery system based on phase conjugation is designed. The transmission system can work without any phase locking loop, resulting in a rapid phase correction. Also the method does not need any phase tunable parts, which means the phase adjusting range is unlimited. An experiment based on this technique is demonstrated, in which a RF signal of 2.42 GHz is transferred through a 30 km fiber link. The capability of rapid phase correction is verified during the experiment. The root mean square (RMS) phase drift of the transferred signal is 0.026 rad within half an hour. After the delay of the link has changed 700 ps, the peak to peak delay jitter of the signal is only 2.73 ps.To enlarge the tuning range when compensating the optical delay, a phase stabilized transmission method taking advantage of the dispersion induced tunable delay is researched and demonstrated. The wavelength of the optical carrier is adjusted according to the delay variation, resulting in a dispersion induced tunable delay, which is used to stabilize the delay variation of the link. The delay tunable range is in proportion to the fiber length, which means a very large delay tuning range can be expected. Experimentally, a 2.42 GHz signal is transferred through a 54 km fiber link with a RMS delay jitter of 0.854 ps. Also the system is capable of transferring wideband signal. In another experiment, two RF signals, at frequencies of 2.46 GHz and 8.00 GHz, are transferred through a 30 km fiber link simultaneously, and significant phase drift compression is realized at both frequencies. To further improve the stability of the system, a piezoelectric fiber delay line is used to cancel the fast and small part of the delay fluctuation. By working together with the dispersion induced delay, large tuning range and fine adjusting granularity can be realized. Experimentally, a 2.48 GHz RF signal is transferred through a 60 km optical fiber link. The fractional frequency stability achieved is 6.5×10-14 at 1s and 2.1×10-17 at 104 s averaging time, respectively.To avoid introducing excess phase variations to the received signals during the frequency conversion at the remote antennas in an antenna array, a phase stabilized downlink transmission technique for wideband RF signal is proposed, which can directly transport the received RF signals from the remote antennas to the processing center. Experimentally, a RF signal at the frequency of 2.50 GHz has been downlink transferred through a 45 km fiber link, with stability of 3.3×10-13 at 1 s and 7.5×10-17 at 104 s.To sum up, the dissertation has researched and designed some phase stabilized transmission systems, which are mainly aiming to improve the existing imperfect ones. The outcome of the work has been applied in the data receiving of the Lunar Radio Measurements system in Beijing Aerospace Control Center, which makes sure that the system can accurately acquire the X band beacon signal of the Chang’e-3 satellite. This technique is expected to be widely used in the exploration program of the deep space in the future.
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