[Gmsh] Question about Quads when using Recombine

[David Tilston]

I've just started using gmsh.  I am trying to create a mesh of quads for
input into a moment method solver for antennas.  As a trial case, I'm
trying a simple square microstrip patch antenna.  The geometry consists of
an outer perimeter representing the ground plane and an inner area where
the patch element is.  One edge on the inner section must have a
sub-section of exactly 1 segment and of specific width and location
(corresponding to the attachment of a microstrip transmission line). So,
I've created Lines with endpoints at the needed locations.  Meshing with
triangles works fine.  However, when I use Recombine to generate quads, the
subsection/segment of interest gets split in two.  I've tried setting
various values for characteristic length but to no avail.  Here's a copy of
my input file:
//~~~~~~~~~~~~~~~~~~~~~~~~
wo = 0.125;
lo = 0.125;
nwo = 8;
nlo = 8;
wi = 0.05;
li = 0.05;
wf = 0.005;
lc1 = 0.025;
lc2 = 0.01;

// Outer perimeter
Point(1) = {0.0, wo/2, -lo/2};
Point(2) = {0.0, wo/2,  lo/2};
Point(3) = {0.0,-wo/2,  lo/2};
Point(4) = {0.0,-wo/2, -lo/2};
Line(101) = {1, 2};
Line(102) = {2, 3};
Line(103) = {3, 4};
Line(104) = {4, 1};
Line Loop(201) = {101, 102, 103, 104};

// Inner perimeter
Point(5) = {0.0, wi/2, -li/2, lc2};
Point(6) = {0.0, wi/2,  li/2, lc2};
Point(7) = {0.0,-wi/2,  li/2, lc2};
Point(8) = {0.0,-wi/2, -li/2, lc2};
Point(9) = {0.0,-wf/2, -li/2, lc2};
Point(10) = {0.0, wf/2, -li/2,lc2};
Line(105) = {5, 6};
Line(106) = {6, 7};
Line(107) = {7, 8};
Line(108) = {8, 9};
Line(109) = {9, 10};
Line(110) = {10, 5};
Line Loop(202) = {105, 106, 107, 108, 109, 110};

// Make the surfaces
Plane Surface(301) = {201, 202};
Physical Surface("Outer") = {301};
Plane Surface(302) = {202};
Physical Surface("Inner") = {302};

// Uncomment to recombine to quads
//Recombine Surface "*";
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I need exactly 1 edge of a quad on the line from point 9 - 10.

Excuse the length of this post.  I'd appreciate any help.

- Dave
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