Constructions of Relative Difference Sets with Classical Parameters and Circulant Weighing Matrices

In this paper, a new family of relative difference sets with parameters (m,n,k,λ) =(q7−1)/(q−1),4(q−1),q6,q5/4) is constructed where q is a 2-power. The construction is based on the technique used in [2]. By a similar method, we also construct some new circulant weighing matrices of order qd−1 where q is a 2-power, d is odd and d⩾5.