Preheat the oven to 200 degrees F.
Line 2 large baking sheets with parchment paper and set aside.
In a small saucepan combine the sugar and water, and dissolve, stirring, over medium-low heat. Add the lemon juice and cardamom, and stir. Remove from the heat and let cool slightly.
With a mandoline or other slicing machine, thinly slice the pears lengthwise to 1/8-inch thickness. Dip the pear slices in the syrup and shake to remove any excess. Arrange the slices tightly in a single layer on the baking sheets.
Bake in the oven until crisp, about 2 to 3 hours, switching the baking sheets several times during the cooking process.