So A(0, -b), F(3b, 0),
So the equation of the straight line L is: x3b+y? B = 1, that is, x-3y-3b=0,
Because the straight line l and the circle c: x2+(y? 2b)2 = 274° tangent,
So |0? 23b? 3b | 2 = 332,b= 1,a=2,
So the equation of ellipse E is: x24+y2 =1;
(2) When PQ, CP and CQ are connected, there is |PQ|≤|CP|+|CQ|=332+|CQ| (if and only if P, C and Q are collinear and P and Q are not normal in C).
So when |CQ| takes the maximum value, |PQ| takes the maximum value.
Let Q(x0, y0) give x024+y02 = 1,
C (0 0,2), then |CQ|=x02+(y0? 2)2=4? 4y02+(y0? 2)2=? 3(y0+23)2+283,
Because y0 ∈ [- 1, 1],-1
Put y0 =? 23 is substituted into x24+y2 = 1, and x0= 253 is obtained.
Therefore, when |PQ| obtains the maximum value, the coordinate of point Q is (253, -23).