GHz Microwave Signal Research Articles

Electro-optic sampling of optoelectronically phase-locked 10.0 GHz microwave signals using semiconductor laser diodes

10.0 GHz microwave signals optoelectronically phase locked by a laser-diode-based GaAs: Cr photoconductive harmonic mixer (λ = 0.81μm) have been measured noninvasively using the electro-optic sampling technique with a gain-switched InGaAsP laser diode (λ = 1.3μm).

Proposal for an X-band single-stage FEL

A single-stage X-band FEL with a high repetition rate (∼ kHz) has been designed and is now under construction at the KEK FEL facility. The microwave FEL will be driven with a 1 MeV, 1 kA electron beam which is generated in the induction gun energized by magnetic switches. A 9.4 GHz microwave signal introduced from the 50 kW magnetron is expected to be amplified to ∼ 300 MW as a result of the interaction with the electron beam in the undulating tapered planar wiggler field. Details of the design including the induction gun, a post-accelerator, a wiggler magnet and an rf measuring system are described. The status and the preliminary operation of the pulsed power system is presented.

A microwave FEL amplifier experiment

An extremely high power gain true free-electron-laser-amplifier experiment on a pulseline accelerator is described, in which an intense electron beam (700 kV, 500 A) with low axial velocity spread (Δβ‖β‖ ⋍ 0.2%) is used and a narrow band 34.5 GHz microwave signal is coherently amplified to several megawatts. An extended interaction oscillator (EIO) is used as the microwave signal source. The signals are sent into the FEL interaction tube through a quasi-optical cavity. Specific efforts are made to optimize the experimental parameters in order to obtain higher power gain.

35 GHz microwave signal generation with an injection-locked laser diode

A new technique for sinusoidal intensity modulation of light, based on injection-locking of two longitudinal modes of a single laser to FM sidebands of another laser, is described. A 35 GHz microwave signal with a linewidth of less than 10 Hz was generated.

An integrated 4GHz balanced transistor amplifier : Thomas E. Saunders and Paul D. Stark, IEEE Trans. Solid-St. CircuitsSC-2, No. 1, March (1967), p. 4

Frequency-sextupled microwave signal generation based on dual-polarization modulation using an electro-optic dual-parallel polarization modulator (DPPolM) without an optical filter is proposed. From a theoretical analysis, the frequency-sextupled microwave signal can be obtained by properly adjusting the polarization directions of the modulated optical signals, the powers and the phases of the microwave drive signals applied to the DPPolM. Simulation results show that a 24 GHz microwave signal with an optical sideband suppression ratio (OSSR) exceeding 31 dB and a radio frequency spurious suppression ratio (RFSSR) higher than 25 dB is generated from a 4 GHz microwave drive signal, which match well with the theoretical analysis. Furthermore, it is also proved to be valid that even if the microwave drive voltage, the phase difference, and the polarization direction of light wave deviate from the ideal values to a certain degree, the performance of the generated frequency-sextupled microwave signal is still acceptable.