Microwave Anisotropy and Frequency Dependence of Hot Electron in n-Type Gaps

The physical mechanism of the microwave anisotropy due to the hot electron effect in a semiconductor bulk is at first investigated phenomenologically for the case that a relative spatial angle θ between a small microwave electric field and a high intensity electric bias field is arbitrary. And then, the microwave anisotropy and the frequency dependence in n -type GaAs are analyzed by using the Boltzmann transport equations. Conclusively, the microwave anisotropy is especially remarkable in the region of negative resistance. Furthermore, as an interesting result, the dependences of both the microwave angular frequency ω and the angle θ in the microwave characteristics are monistically determined by only one factor ≡ω/cos θ under the proper condition of ωτ (τ: relaxation time), which is satisfied in the region of negative resistance.