  We present measurements of the microwave complex surface impedance at 47.7
GHz in YBa$_2$Cu$_3$O$_{7-\delta}$ (YBCO) films deposited by pulsed laser
deposition with the explicit goal to introduce BaZrO$_3$ (BZO) nanoinclusions.
Composite targets obtained by addition of BZO powder in molar percents ranging
from 2.5 to 7 mol.% have been prepared and characterized. Measurements of the
microwave surface impedance indicate a broadened transition in zero field,
however compensated by a very large pinning frequency, indicating that while
intergrain properties are still to be optimized the effect of nanometric
inclusions substantially enhances the intragrain vortex pinning.
