double tuned double tuned tuned stages primary secondary tuned separately scheme results wider skirts single tuned circuit achieve critical value frequency response flat gain maximum frequency designs frequently use greater order achieve wider expense small loss gain centre multiple stages double tuned results reduction overall stages double tuned single stage alternative double tuning avoids loss tuning tuned designed prescribed greater single stage tuning requires stages lower gain double tuning typical circuit circuit shown consists stages common bias serve usual functions input stage coupled conventional way series avoid affecting bias collector load consists serves inter stage instead placed form circuits provide tuning detail seen kind presence input output connections matching purposes junction kind shown circuit high output low input problem avoided high input connected secondary ground form tuning purpose bias circuit properties double tuning compared single tuning effect widening skirt response tuning sides forms pair coupled source increased gain function related mutual primary secondary winding respectively formula critical value gain maximum resonance critical value single peak frequency response peaking resonance peak decreasing decreases response said values critical response starts split peaks peaks narrower apart increases gap centred frequency progressively deeper response said critically coupled response flat response achieved stages tuned unlike tuning double tuning usually tunes frequency designer choose design order achieve wider expense small dip typically centre frequency response like tuning adding stages double tuned effect reducing identical stages fraction single stage given approximately formula expression applies small analysis circuit represented generic way replacing shown stage number output input typically design frequencies primary secondary sides identical formula formula frequency expressed units angular frequency refer respectively components primary secondary stage gain assumptions voltage gain stage expressed formula formula imaginary unit formula maximum gain stage formula frequency expressed frequency frequency peak frequency critical peak response occurring resonance critical peaks frequencies given formula respectively low high frequencies peaks expressed critical peaks reach maximum gain available critical critical occurs peaks coincide formula formula
Double-tuned amplifier