Microwave integrated circuit frequency converter

• US 4,531,236 A
• Filed: 12/08/1982
• Issued: 07/23/1985
• Est. Priority Date: 12/11/1981
• Status: Expired due to Fees

• Current Assignee: Nippon Electric Company Limited (NEC Corporation)
• Original Assignee: Nippon Electric Company Limited (NEC Corporation)
• Inventors: Ishihara, Hiroyuki
• Primary Examiner(s): NG, JIN FAY
• Application Number:
  US06/447,826
• Time in Patent Office: 958 Days
• Field of Search: 455/302, 455/317, 455/325-328, 455/330
• US Class Current: 455/302
• CPC Class Codes: H03D 2200/0037 Diplexers
• CPC Class Codes: H03D 7/18 Modifications of frequency-changers for eliminating image frequencies H03D7/16 takes precedence
• CPC Class Codes: H03D 9/0608 by means of diodes
• CPC Class Codes: H03D 9/0633 mounted on a stripline circuit

Abstract

A microwave integrated circuit frequency converter includes a first filter (30) for a signal frequency and a second filter (32) for a local oscillator frequency connected at one terminal thereof with one terminal of the signal frequency filter (30) by a line (38), (40) having a predetermined electrical length. A parallel stub line (42) is short-circuited at one end thereof. A diode (34) is connected at its one end to a third filter (36) which is adapted to reflect the signal and local oscillator frequencies while passing an intermediate frequency. The diode (34) is connected at the other end to a line (41). The parallel stub line (42) and line (41) are connected at their other ends to a specific junction P on the connecting line (38), (40) at which the impedance is open circuited for the signal frequency when the local oscillator frequency filter (32) is seen from the signal frequency filter (30) side and the impedance is open circuited for the local oscillator frequency when the signal frequency filter (30) is seen from the local oscillator frequency filter (32) side.

Claims

1. A microwave integrated circuit frequency converter comprising:

first bandpass filter means having an input connected to receive a signal frequency;

second bandpass filter means having an input connected to receive a local oscillator frequency;

first transmission line means connecting an output of the first bandpass filter means to a junction;

second transmission line means connecting an output of the second bandpass filter means to the junction;

low pass filter means constructed to pass an intermediate frequency and reflect the signal and local oscillator frequencies and an image frequency;

third transmission line means connecting the low pass filter means to the junction;

diode means coupled between the third transmission line means and an input of the low pass filter means; and

parallel stub line means having one end short-circuited and another end connected to the junction,

electrical lengths of the first and second transmission line means and the parallel stub line means being selected so that an impedance seen from the junction is open-circuited to the signal frequency and the local oscillator frequency,

the electrical length of the third transmission line means being selected so that an impedance seen from the diode is open-circuited or short-circuited for the image frequency.

2. A microwave integrated circuit frequency converter comprising:

first bandpass filter means having an input connected to receive a signal frequency and passing substantially only said signal frequency;

second bandpass filter means having an input connected to receive a local oscillator frequency and passing substantially only said local oscillator frequency;

first transmission line means connecting an output of the first bandpass filter means to a junction;

second transmission line means connecting an output of the second bandpass filter means to the junction;

low pass filter means constructed to pass an intermediate frequency and reflect the signal and local oscillator frequencies and an image frequency;

diode means coupled between the junction and an input of the low pass filter means;

a first parallel stub line means having one end short-circuited and another end connected to the junction, and a second parallel stub line means having one end open-circuited and another end connected to the junction;

electrical lengths of the first and second transmission line means and the first and second parallel stub line means being selected so that an impedance seen from the junction is open-circuited to the signal frequency and the local oscillator frequency.