Flip-chip MMIC oscillator assembly with off-chip coplanar waveguide resonant inductor

A microwave monolithic integrated circuit (MMIC) oscillator assembly, comprising:

• an electrically insulative substrate;
• a MMIC chip which is flip-chip mounted on the substrate and includes:
• active oscillator element means;
• resonant capacitor means;
• and
• coplanar waveguide means interconnecting the active oscillator element means and resonant capacitor means;
• resonant inductor means including a shorted coplanar waveguide section formed on the substrate;
• and
• electrical connector means interconnecting the resonant capacitor means and resonant inductor means to form a resonant circuit of the oscillator assembly.

A method of fabricating a microwave frequency inductor on an electrically insulative substrate, comprising the steps of:

• (a) forming a shorted coplanar waveguide section on the substrate, the waveguide section including first and second ground strips, a conductor strip extending between the first and second ground strips in parallel relation thereto and being separated therefrom by first and second spaces respectively, and a shorting strip for electrically interconnecting adjacent first ends of the conductor strip and first and second ground strips respectively;
• (b) forming a dielectric film over at least adjacent portions of the conductor strip and first and second ground strips;
• (c) sensing the inductance of the waveguide section;
• (d) removing part of the dielectric film from at least one of the first and second spaces;
• and
• (e) repeating steps (c) and (d) until the sensed inductance is substantially equal to a predetermined value.

A method of fabricating a microwave frequency inductor on an electrically insulative substrate, comprising the steps of:

• (a) forming a shorted coplanar waveguide section on the substrate, the waveguide section including first and second ground strips, a conductor strip extending between the first and second ground strips in parallel relation thereto and being separated therefrom by first and second spaces respectively, and a shorting strip for electrically interconnecting adjacent first ends of the conductor strip and first and second ground strips respectively;
• (b) sensing the inductance of the waveguide section;
• (c) removing part of the shorting strip at the first end of at least one of the first and second spaces respectively;
• and
• (d) repeating steps (b) and (c) until the sensed inductance is substantially equal to a predetermined value.

A method of fabricating a microwave monolithic integrated (MMIC) oscillator assembly, comprising the steps of:

• (a) providing an electrically insulative substrate;
• (b) fabricating a MMIC chip including active oscillator element means, resonant capacitor means, and coplanar waveguide means interconnecting the active oscillator element means and resonant capacitor means;
• (c) forming resonant inductor means including a shorted coplanar waveguide section on the substrate, the waveguide section including first and second ground strips;
• a conductor strip extending between the first and second ground strips in parallel relation thereto and being separated therefrom by first and second spaces respectively;
• and a shorting strip for electrically interconnecting adjacent first ends of the conductor strip and first and second ground strips respectively;
• (d) forming a dielectric film over at least adjacent portions of the conductor strip and first and second ground strips;
• (e) flip-chip mounting the MMIC chip on the substrate such that the resonant capacitor means and resonant inductor means are interconnected to form a resonant circuit of the oscillator assembly;
• (f) sensing the oscillation frequency of the resonant circuit;
• (g) removing part of the dielectric film from at least one of the first and second spaces;
• and
• (h) repeating steps (f) and (g) until the sensed oscillation frequency is substantially equal to a predetermined value.

A method of fabricating a microwave monolithic integrated (MMIC) oscillator assembly, comprising the steps of:

• (a) providing an electrically insulative substrate;
• (b) fabricating a MMIC chip including active oscillator element means, resonant capacitor means, and coplanar waveguide means interconnecting the active oscillator element means and resonant capacitor means;
• (c) forming resonant inductor means including a shorted coplanar waveguide section on the substrate, the waveguide section including first and second ground strips, a conductor strip extending between the first and second ground strips in parallel relation thereto and being separated therefrom by first and second spaces respectively, and a shorting strip for electrically interconnecting adjacent first ends of the conductor strip and first and second ground strips respectively;
• (d) flip-chip mounting the MMIC chip on the substrate such that the resonant capacitor means and resonant inductor means are interconnected to form a resonant circuit of the oscillator assembly;
• (e) sensing the oscillation frequency of the resonant circuit;
• (f) removing part of the shorting strip at the first end of at least one of the first and second spaces respectively;
• and
• (g) repeating steps (e) and (f) until the sensed oscillation frequency is substantially equal to a predetermined value.