Filtering device and a method for filtering a signal

A method for filtering an input signal, the method comprising:

• providing an input signal;
• complementary filtering the input signal according to a complementary filtering characteristic, the complementary filtering characteristic comprising at least one complementary pass band and at least one complementary stop band;
• substantially transforming a first filtering characteristic with at least a first pass band and at least a first stop band into an effective filtering characteristic;
• wherein the effective filtering characteristic and the complementary filtering characteristic are closely spaced in frequency, and combine to provide an overall filtering characteristic,
• and wherein a step of the first filtering providing the first filtering characteristic and the step of the complementary filtering are chosen to provide substantially identical responses to temperature changes.

A computer program product embodied on a computer readable medium and the computer-readable medium comprising executable instructions for the execution of a manufacture of a filtering device, the filtering device comprising:

• a first filtering element having a first filtering characteristic with at least a first pass band and at least a first stop band;
• a complementary filtering unit with a complementary filtering characteristic comprising at least one complementary pass band and at least one complementary stop band;
• a transforming unit is adapted to substantially transform at least the first filtering characteristic of the first filtering element into an effective filtering characteristic;
• wherein the effective filtering characteristic and the complementary filtering characteristic
• are closely spaced in frequency and combine to provide an overall filtering characteristic of the filtering device;
• and wherein the overall filtering characteristic affects an output signal at an output of the filtering device in response to an input signal at an input of the filtering device;
• and wherein a response to temperature changes of the first filtering element is substantially identical to a response to temperature changes of the complementary filtering unit.

A computer program product embodied on a computer readable medium and the computer-readable medium comprising executable instructions for the execution of a method for filtering an input signal, the method comprising the steps of:

• providing an input signal;
• filtering the input signal according to a complementary filtering characteristic, the complementary filtering characteristic comprising at least one complementary pass band and at least one complementary stop band;
• substantially transforming a first filtering characteristic with at least a first pass band and at least a first stop band into an effective filtering characteristic;
• wherein the effective filtering characteristic and the complementary filtering characteristic are closely spaced in frequency and combine to provide an overall filtering characteristic.