Polar codes are a class of codes discovered recently,which are proved to have capacity-achieving performance.Driven by its low complexity decoding algorithm,the designs for successive cancellation(SC)decoders are booming these days.However,the throughput of these decoders are still too low.According to the characteristics of its internal structure,we proposed a family of look-ahead mixed-radix SC decoders for the first time.This is a good tradeoff between hardware resource and throughput.A look-ahead radix-4 SC decoder increases the throughput by 50%compared to the SC decoder while having no loss in decoding performance and almost no excess hardware consumption.Whats more,mixed-radix architectures have good universality and can be inserted into other high-throughput schemes.