Circuit module

A circuit module, comprising:

• a circuit board having a ground;
• one or more electronic components provided on the circuit board;
• a resin mold provided on the circuit board so as to seal the one or more electronic components in an insulating manner;
• a conductive shield covering a top surface and side surfaces of the resin mold;
• and
• a plurality of conductive poles provided in the resin mold, the plurality of conductive poles connecting a top surface of the conductive shield and the ground of the circuit board,
• wherein all of a plurality of rectangular regions on the top surface of the conductive shield have two sides with lengths of a and b satisfying Formula (1) expressed as:
• f
• max
• <
• c
• 2
• 
• π
• 
• ɛ
• r
• 
• (
• m
• 
• 
• π
• a
• )
• 2
• +
• (
• n
• 
• 
• π
• b
• )
• 2
• (
• 1
• )
• where fmax is a predetermined maximum usable frequency, ∈r is a relative dielectric constant of the resin mold, m and n are any integers, and c is a light speed, each of the plurality of rectangular regions being defined by side surfaces of the conductive shield and one or more of the plurality of conductive poles, each of the plurality of rectangular regions including none of the plurality of conductive poles, and
• wherein the plurality of conductive poles are arranged such that a distance between two closest conductive poles is equal to or less than one-fourth of a wavelength at the predetermined maximum usable frequency in the resin mold.