Unterschiede

Hier werden die Unterschiede zwischen zwei Versionen angezeigt.

--- projekte:6cmtrv:start [2025/12/16 00:23] – yc
+++ projekte:6cmtrv:start [2025/12/16 01:35] (aktuell) – yc
@@ Zeile 4: / Zeile 4: @@
 Objectives:
   * Output power > 1 W
-  * Receive noise figure < 3 dB NF
+  * Receive noise figure < 2 dB NF
   * Integrated IF and RF transmit/receive switches
   * Integrated stable and clean local oscillator
+**[[https://git.loetlabor-jena.de/yc/6cm_trv|design repository (Gitlab)]]**
 ===== Preface =====
 For many years low-cost LNBs enable people to have very easy access to 10 GHz reception. It's size and ease of use makes it enjoyable to use in many situations. For the 6 cm band no comparable solution is known.
@@ Zeile 29: / Zeile 31: @@
 ===== Implementation =====
-Like in previous projects ([[..:lofourx:start|10 GHz Multiplier]], [[..:3cmbeacon:start|10 GHz Beacon]]) CPWG transmission lines on a four-layer stackup are used. The RF design is based on the well-characterized coaxial/PCB transition and uses a complete coplanar transmission design to interface to all QFN components with a GND-signal-GND for simple continuous impedance control. As all components are internally matched no additional on-board matching is required.
+Like in previous projects ([[..:lofourx:start|10 GHz Multiplier]], [[..:3cmbeacon:start|10 GHz Beacon]]) CPWG transmission lines on a four-layer stackup are used. The RF design is based on the well-characterized coaxial/PCB transition and uses a complete coplanar transmission design to interface to all QFN components in GND-signal-GND style for continuous impedance behavior. For the large pads of the bandpass filters an individual footprint was designed and simulated for proper 50 Ohm interfacing on the thin substrate used. As all other components are internally matched no further on-board matching is required.
+{{:projekte:6cmtrv:6cmtrv_pcb.jpg?400|}}
+In transmit mode 7.5 watts of heat is dissipated. For proper heat sink the PCB is directly connected to the housing with attached heatsink.
+{{:projekte:6cmtrv:6cmtrv_front.jpg?400|}} {{:projekte:6cmtrv:6cmtrv_back.jpg?400|}}
+Front and back panels are low-cost PCBs with black solder mask and white silk screen. LEDs are placed on the back panel to show the current state state.
+^ State ^ RX ^ TX ^ HT ^ PWR ^
+| heating | off | off | blinking \\ blink speed depends on OCXO current | off |
+| receiving | on | off | on | all good \\ LO locked and power good |
+| transmitting | off | on | on | high power \\ on for current power above 1 W |
+===== Testing =====
+The first prototype was characterized after final assembly. The maximum output power is 29 dBm with 100 mW input power and a noise figure of 3.1 dB is achieved. With 1 dB of switch loss and additional transmission line attenuation the results seem reasonable but noise figure needs some investigation, 1.6 dB was intended.
+The phase noise in transmit mode is surprisingly good without any optimization:
+{{:projekte:6cmtrv:6cmtrv_pn.png|}}