Hi, Group.

On Fri, 25 Apr 2003, Rik Strobbe wrote:

At the upper leg : SIN(A) * COS(B) = SIN(A+B) + SIN(A-B) (ignoring the divide by 2)

after the 90 degrees phase shift at the output = COS(A+B) + COS(A-B)

At the lower leg : SIN(A)*SIN(B) = COS(A-B) - COS(A+B)

Adding : COS(A+B) + COS(A-B) + COS(A-B) - COS(A+B) = 2*COS(A-B)
Subtracting : COS(A+B) + COS(A-B) - COS(A-B) + COS(A+B) = 2*COS(A+B)

So that way theory seems OK.

And it is pointly the same way to depress undesired product wich was
used many years ago for SSB forming by a phase method. This
method was widely used in 50-th.

73 de RA9MB/Alex
http://www.qsl.net/ra9mb