Low noise block down converter with a plurality of local oscillators

• US 20040072550A1
• Filed: 08/18/2003
• Published: 04/15/2004
• Est. Priority Date: 10/09/2002
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Motoyama, Koji
• Granted Patent: US 7,177,618 B2
• Time in Patent Office: Days
• US Class Current: 455/323
• CPC Class Codes: H01P 1/2084 with dielectric resonators
• CPC Class Codes: H01Q 1/247 with frequency mixer, e.g. for direct satellite reception or Doppler radar

Abstract

A low noise block down converter accommodates two local oscillators within one shielding chamber in a metal shielding box and has a conductive bar provided between two dielectric resonators included in the local oscillators respectively. The conductive bar prevents electromagnetic coupling between the two dielectric resonators. Therefore, the device dimension can be made small compared to the conventional case in which two local oscillators are completely separated from each other by a metal wall.

Claims

1. A low noise block down converter, comprising:

a plurality of local oscillators each including a dielectric resonator and having an oscillation frequency different from each other;

an electromagnetic coupling preventing member preventing electromagnetic coupling between one and another one of said dielectric resonators; and

a metal shielding box including one shielding chamber accommodating said plurality of local oscillators and said electromagnetic coupling preventing member.

2. The low noise block down converter according to claim 1, wherein said electromagnetic coupling preventing member includes a conductive bar having one end extending between any two of said dielectric resonators and receiving a reference potential.

3. The low noise block down converter according to claim 1, further comprising a substrate having a surface on which said plurality of local oscillators are mounted, wherein

said electromagnetic coupling preventing member includes a conductive pattern formed on the surface of said substrate between any two of said dielectric resonators and receiving a reference potential.

4. The low noise block down converter according to claim 1, wherein said electromagnetic coupling preventing member includes a metal plate provided between any two of said dielectric resonators and receiving a reference potential.