Abstract:
A method (100) for tuning a voltage controlled oscillator by changing electrical circuit parasitics includes a first step (102) of providing a voltage controlled oscillator circuit on a circuit board and a plurality of different metal lids each having different numbers, sizes and locations of holes. Each different lid presents a different electrical circuit parasitic to the voltage controlled oscillator. In a second step (104), the voltage controlled oscillator frequency is measured, and the frequency shift needed to achieve a desired operating frequency is calculated in a third step (106). In a fourth step (108), a lid is chosen that will present the parasitics needed to provide the amount of frequency shift needed. As a last step (110), the chosen lid is attached to the circuit board to obtain the desired nominal operating frequency from the voltage controlled oscillator.
Abstract:
A coplanar waveguide based microwave monolithic integrated circuit (MMIC) oscillator chip (14) has an active oscillator element (16) and a resonant capacitor (18) formed thereon and is flip-chip mounted on a dielectric substrate (12). A resonant inductor (22) is formed on the substrate (12) and interconnected with the resonant capacitor (18) to form a high Q-factor resonant circuit for the oscillator (10). The resonant inductor (22) includes a shorted coplanar waveguide section (24) consisting of first and second ground strips (24b, 24c), and a conductor strip (24a) extending between the first and second ground strips (24b, 24c) in parallel relation thereto and being separated therefrom by first and second spaces (26a, 26b), respectively. A shorting strip (24d) electrically interconnects adjacent ends of the conductor strip (24a) and first and second ground strips (24b, 24c), respectively. A dielectric film (34) may be formed over at least adjacent portions of the conductor strip (24a) and first and second ground strips (24b, 24c). The resonant inductor (22) is adjusted to provide a predetermined resonant frequency for the oscillator (10) by using a laser to remove part of the dielectric film (34) in the first and second spaces (26a, 26b) for fine adjustment, and/or to remove part of the shorting strip (24d) at the ends of the first and second spaces (26a, 26b) for coarse adjustment.
Abstract:
Die Erfindung bezieht sich auf einen modulierbaren Transistoroszillator großer Leistung für den Bereich sehr hoher Frequenzen. Bei diesem soll die modulierte Radiofrequenz in einem einstufigen Leistungsoszillator erzeugt wer - den bei einer möglichst verzerrungsfreien Erzeugung des erforderlichen Frequenzhubs bei hohem Leistungspegel des RF-Oszillators und möglichst geringem thermischen Geräusch. Die Erfindung sieht hierzu vor, daß das verstärkte Basisbandsignal über zwei Wege gleichphasig dem Oszillator zugeführt wird derart, daß einerseits über einen Vorspannungstransistor (Tr 2) die Basisvorspannung des RF-Transistors (TR 1) moduliert und andererseits über eine Modulationsdiode (22) die Frequenz des mit dem RF-Transistor (Tr 1) verbundenen Resonators (1) geändert wird. Ein erfindungsgemäßer Transistoroszillator ist insbesondere für den Einsatz in direkt modulierten Richtfunksystemen geeignet (Fig. 1).
Abstract:
튜너 회로는, 제1의 IF 신호를 출력하기 위한 제1의 IF 신호 생성 회로, 국부 발진 신호를 출력하기 위한 국부 발진 회로(110)와, 제1의 IF 신호와 국부 발진 신호를 믹싱하여 제2의 IF 신호를 생성하기 위한 믹싱 회로(109)와, 적어도 국부 발진 회로가 그 위에 형성되는 제1의 기판(4)을 포함한다. 국부 발진 회로(110)는, 발진 회로(116)와, 발진 회로(116)에 접속되며 습도나 경년 변화에 의한 발진 주파수의 변화의 영향을 보정하기 위한 동축 공진기(115)를 포함한다. 동축 공진기(115)는 발진 주파수를 조정하기 위한 임피던스 가변 트리머(5)와, 제1의 기판(4)에 대하여 고정된 위치에 설치된 중심도체(1)와, 임피던스 가변 트리머(5)와 중심도체(1)와의 사이를 절연하기 위한 절연물을 포함한다. 임피던스 가변 트리머(5)와 중심도체(1)와는 절연물을 개재하여 밀착하고 있다.