Voltage-controlled oscillator and method for adjusting frequency shift amount thereof

In a voltage-controlled oscillator having a structure that a strip-line is employed as a resonator, a center tap is provided in the strip-line of said resonator, a switching element is connected to said center tap, and said center tap is electrically shortcircuited to the ground by turning ON said switching element so as to vary an oscillating frequency, a method for adjusting a frequency shift amount of the voltage-controlled oscillator comprises a step of:

• forming at least one slit in the strip-line to change an inductance of the strip-line to thereby adjust an amount of a frequency shift,
• wherein said at least one slit comprises a first slit formed along the strip-line located in vicinity of said center tap and directed to a shortcircuited end side of the strip-line to thereby adjust said amount of said frequency shift.

In a voltage-controlled oscillator having a structure that a strip-line is employed as a resonator, a center tap is provided in the strip-line of said resonator, a switching element is connected to said center tap, and said center tap is electrically shortcircuited to the ground by turning ON said switching element so as to vary an oscillating frequency, a method for adjusting a frequency shift amount of the voltage-controlled oscillator comprises a step of:

• forming at least one slit in the strip-line to change an inductance of the strip-line to thereby adjust an amount of a frequency shift, wherein the at least one slit comprises a first slit formed along the strip-line located in the vicinity of a shortcircuited end side of the strip-line and directed to said center tap to thereby adjust an amount of a frequency shift.

In a voltage-controlled oscillator having a structure that a strip-line is employed as a resonator, a center tap is provided in the strip-line of said resonator, a switching element is connected to said center tap, and said center tap is electrically shortcircuited to the ground by turning ON said switching element so as to vary an oscillating frequency, a method for adjusting a frequency shift amount of the voltage-controlled oscillator comprises a step of:

• forming a slit in the strip-line above said center tap to change an inductance of the strip-line to thereby adjust an amount of a frequency shift, wherein the slit is formed in a transverse direction of said strip-line and configured, upon trimming, to decrease said operating frequency without substantially changing an amount of frequency shift.

In a voltage-controlled oscillator having a structure that a strip-line is employed as a resonator, a center tap is provided in the strip-line of said resonator, a switching element is connected to said center tap, and said center tap is electrically shortcircuited to the ground by turning ON said switching element so as to vary an oscillating frequency, a method for adjusting a frequency shift amount of the voltage-controlled oscillator comprises a step of:

• forming at least one slit in the strip-line to change an inductance of the strip-line to thereby adjust an amount of a frequency shift, wherein trimming points are defined on a side of a hot terminal of said strip-line from said center tap and on a side of a short-circuited end of said strip from said center tap;
• and
• the at least one slit is formed in at least any one of said trimming points in a transverse direction of said strip line.