Common mode filter provided with hightened removal function of common mode noise and de-emphasis function

A common mode filter comprising:

• at least one common mode filter portion configured to remove a common mode noise, the at least one common mode having a first terminal pair configured to include first and second terminals connected to first and second external terminals, respectively, and having a second terminal pair configured to include third and fourth terminals connected to third and fourth external terminals, respectively;
• and
• a filter circuit connected between the first terminal pair of the common mode filter portion and the first and second external terminals,
• wherein the filter circuit comprises:
• a first reactance circuit connected between the first terminal of the common mode filter portion and the first external terminal, the first reactance circuit being configured to include a parallel circuit of a series circuit of two resistors and a capacitor;
• a second reactance circuit connected between the second terminal of the common mode filter portion and the second external terminal, the second reactance circuit being configured to include a parallel circuit of a series circuit of two resistors and a capacitor;
• a third reactance circuit connected between a connection point of the two resistors of the first reactance circuit and a fifth external terminal, the third reactance circuit being configured to include a series circuit of a resistor and an inductor;
• and
• a fourth reactance circuit connected between a connection point of the two resistors of the second reactance circuit and the fifth external terminal, the fourth reactance circuit being configured to include a series circuit of a resistor and an inductor,
• wherein the fifth external terminal is for being directly or indirectly grounded.

A common mode filter comprising:

• at least one common mode filter portion configured to removes a common mode noise, the at least one common mode filter portion having a first terminal pair configured to include first and second terminals connected to first and second external terminals, respectively, and having a second terminal pair configured to include third and fourth terminals connected to third and fourth external terminals, respectively;
• a filter circuit connected between the first terminal pair of the common mode filter portion and the first and second external terminals;
• a sixth external terminal connected to the first terminal of the common mode filter portion;
• and
• a seventh external terminal connected to the second terminal of the common mode filter portion,
• wherein the filter circuit comprises:
• a first circuit connected between the first terminal of the common mode filter portion and the first external terminal, the first circuit including a series circuit of two resistors;
• a second circuit connected between the second terminal of the common mode filter portion and the second external terminal, the second circuit including a series circuit of two resistors;
• a third reactance circuit connected between a connection point of the two resistors of the first circuit and a fifth external terminal, the third reactance circuit being configured to include a series circuit of a resistor and an inductor;
• and
• a fourth reactance circuit connected between a connection point of the two resistors of the second circuit and the fifth external terminal, the fourth reactance circuit being configured to include a series circuit of a resistor and an inductor,
• wherein the fifth external terminal is for being directly or indirectly grounded,
• wherein a first variable capacitor is to be connected between the first external terminal and the sixth external terminal, and
• wherein a second variable capacitor is to be connected between the second external terminal and the seventh external terminal.