Land Mobile

Land Mobile | Planar antenna aperture

• Specification of the aperture area with the aim of minimizing the overall height of the system
• The form factor significantly determines antenna gain and antenna radiation pattern
• Determination of 15 Tx modules and 8 Rx modules, resulting in dimensions of 110cm x 30cm
• Specification of electrical and mechanical interfaces
• Coordination with the aperture supplier (technical, commercial, and logistical)
• Development, manufacturing, assembly, and measurement of the aperture modules

Land Mobile | EBF Implementation

• Active implementation of the Rx aperture to achieve electronic beamforming
• Beam steering through adjustable phase shifts of the 8 Rx sub-modules
• Integration of EBF (Electronic Beamforming) functionality into the antenna aperture and coordination regarding mechanical and electrical interfaces
• Development of high-level drivers for beam steering by a few tenths of a degree by the subcontractor IMST
• Examination of the effects on the antenna radiation pattern in both co-polar and cross-polar planes and optimization as necessary

Land Mobile | Mechanical design

• Implementation of the planar aperture at optimal suspension points for minimum radome size
• Removal of the roll axis to reduce body height and weight

• Inclusion of results derived from vibration tests (e.g. use of closed profiles; preference for bolted over riveted connections).
• Development of a cabling concept for the revised prototype mechanics
• Generation of the individual part manufacturing data from the revised 3D design
• Selection of suitable manufacturers as well as data exchange and coordination of offers
• Assembly of subassemblies from supplied parts and their verification

Drive

Elevation module:

• Drive via semi-circular roller track
• Drive arches on the back of the aperture
• 2-stage toothed belt drive
• Drive on both sides via central, rigid drive shaft

Azimuth Module:

• Planetary gear and transmission belt with large gear and flat bearing with large hollow shaft
• Stepping motor
• 2-channel rotary joint in U-configuration
• Slip rings

Land Mobile | Radome

• Main task: Protecting the antenna system from environmental influences
• Compromise of mechanical stability, electromagnetic losses and production costs
• Selection of the basic material composition and measurement of selected layer structures
• Determination of the radome set-up after mechanical and metrological evaluation of the candidates in question.
• Adaptation of the radome construction to the final mechanical design and to the chosen manufacturing process
• Generation of CAD data for toolmaking
• Coordination of toolmaking and sample production
• Metrological evaluation of the prototype radome

Land Mobile | System control

• Replacement of the combination of satellite tuner and DVB-S2 demodulator by integrated satellite tuner with DVB-S2X demodulator
• Integration of a second signal processing path consisting of baseband converter, analogue filter stage, high-speed ADC and FPGA for the implementation of pure power-level based tracking
• 10 MHz continuity in the Rx signal path
• Load and temperature tests with ambient temperatures up to 55°C
• No failures detected in the tested electronics during vibration and shock tests
• Integration of a ventilation system inside the electronics
• Extension of the electronics by an RS485 interface to control the active part of the planar aperture

Landmobil | Stromversorgung

• 19″ 1 U form factor for the indoor units
• Further development of the power electronics for generating the voltages of BUC and ODU
• Vibration and shock tests carried out showed no failures or malfunctions of the power electronics
• Extension of the display options in the web interface and display to include diagnostic values from environmental sensors and power supply monitoring
• Selection of a 19 inch 1U rack inverter with 12 V / 24 V input and 220 V / 50 Hz true sine wave output to supply modem, ACU and ODU
• Function test of the inverter in connection with online UPS and other consumers in the laboratory and in the car
• Environmental tests with all components

Land Mobile | Polarizer

• Connection of BUC and LNB to planar aperture
• Design of a waveguide combiner to transmit the output signals of the active Rx electronics to the LNB
• Realisation of circular polarisation in the receive path by means of programmable phase shifting of the two orthogonal waveguide feeds
• Development of a hybrid coupler for feeding the Tx aperture and generating the circular polarisation
• Optimisation of the hybrid coupler to compensate for existing differences in the phase delays of the waveguide networks
• Construction of the mounting concept in coordination with the aperture supplier
• Testing of the feed network of the Rx aperture
• Implementation of high-level functions for polarization selection in the Rx path

Land Mobile | High-speed 3D-Sensor-Module

• Confirmation of the specification and sizing of the hardware for the Inertial Sensor Module
• Revision of the tracking algorithm
• Design of an extended Kalman filter and its implementation into the sensor module
• To offload the system control, the calculation of target angles is done directly in the sensor module
• Integration of a Second Stage Bootloader and support for encrypted Over-The-Air updates
• Software development for conducting fully automated temperature calibrations
• Adjustment of target angle calculations for the modified axis arrangement of the positioner
• Verification of the optimized assembly on the motion simulator and in a motor vehicle.