Abstract: A microwave amplifier device with a bypass segment, the device operating either in active mode or in bypass mode. The bypass segment (2) comprises at least one section (13) of coupled transmission lines (14,15) whereby the isolation is increased. The amplifier unit (1) includes two LNAs arranged in parallel in a balanced configuration, and the bypass segment (2) has a relatively high input impedance in active mode, whereby a balanced operation of the amplifier unit is maintained. Consequently, a low noise factor is obtained, as well as reduced input and output reflections.

Abstract: A four port hybrid microstrip circuit of modified Lange type, comprising a microstrip pattern including a first strip conductor between an input port (P1) and a direct port (P2) and a second strip conductor between an isolated port (P3) and a coupled port (P4). These two conductors are divided into parallel sections being mutually interdigitated and divided ibnto two parts (10,20) located side by side to each other.

Abstract: A four port hybrid microstrip circuit of modified Lange type, comprising a microstrip pattern including a first strip conductor between an input port (P1) and a direct port (P2) and a second strip conductor between an isolated port (P3) and a coupled port (P4). These two conductors are divided into parallel sections being mutually interdigitated and divided ibnto two parts (10,20) located side by side to each other.

Abstract: A microwave amplifier device with a bypass segment, the device operating either in active mode or in bypass mode. The bypass segment (2) comprises at least one section (13) of coupled transmission lines (14,15) whereby the isolation is increased. The amplifier unit (1) includes two LNAs arranged in parallel in a balanced configuration, and the bypass segment (2) has a relatively high input impedance in active mode, whereby a balanced operation of the amplifier unit is maintained. Consequently, a low noise factor is obtained, as well as reduced input and output reflections.

Abstract: The present invention relates to a four port hybrid comprising a first set (10) of N coupled transmission lines (10A, 10B, 10C, 10D, 10E, 10F, 10G, 10H, 10I) and a second set (20) of N coupled transmission lines (20A, 20B, 20C, 20D, 20E, 20F, 20G, 20H, 20I) where N≧4. Said coupled transmission lines in said first set (10) are electrically connected to said coupled transmission lines in said second set (20) to form a first spiral shaped electrical conductive path, a second spiral shaped electrical conductive path and N−1 electrically isolated transposition portions (30, 40, 50, 60, 70, 80, 90, 110) of said first and second spiral shaped electrical conductive paths. A first end of the first spiral being an input port (P1). A first end of the second spiral being a port (P4) connectable to ground. A second end of the first spiral being a first output port (P3) and a second end of the second spiral being a second output port (P2).

Abstract: A frequency converter for a microwave system includes: a balun having a slot line connected in a parallel T-junction with a first microstrip line for receiving a radio frequency signal; first and second strip lines respectively disposed on either side of the first microstrip line; second and third microstrip lines respectively connected to outer ends of the first and second strip lines to provide signal paths for inputting local oscillation signals and for outputting intermediate frequency signals; first and second open end circuits respectively connected to both ends of the slot line, and a quad diode mixer bridge having a pair of diode connection points connected to the slot line and having another pair of diode connection points respectively connected to the second and third microstrip lines, the radio frequency signal and local oscillation signals being converted into corresponding intermediate signals therein.